Agronomy

12 pages, 1495 KiB

Open AccessArticle

Monitoring the Bud Mite Pest in a Hazelnut Orchard of Central Italy: Do Plant Height and Irrigation Influence the Infestation Level?

by Mario Contarini, Luca Rossini, Nicolò Di Sora, Enrico de Lillo and Stefano Speranza

Agronomy 2022, 12(8), 1982; https://doi.org/10.3390/agronomy12081982 - 22 Aug 2022

Cited by 10 | Viewed by 2253

Abstract

Mite pests are a serious threat for hazelnut cultivations, causing economic losses every year. At least two species of big bud mites, Phytoptus avellanae (Acari: Phytoptidae) and Cecidophyopsis vermiformis (Acari: Eriophyidae), are involved in severe hazelnut bud infestations, even though few studies report [...] Read more.

Mite pests are a serious threat for hazelnut cultivations, causing economic losses every year. At least two species of big bud mites, Phytoptus avellanae (Acari: Phytoptidae) and Cecidophyopsis vermiformis (Acari: Eriophyidae), are involved in severe hazelnut bud infestations, even though few studies report P. avellanae as the most present and harmful. Great steps forward have been made in monitoring and management strategies of these mite pests, but a plethora of questions remains unanswered about their ecology and behaviour and how agronomical practices impact populations. Given this precondition, we conducted a four-year monitoring in an experimental hazelnut orchard located in the Viterbo hazelnut district, Central Italy, to: (i) explore the potential effect that irrigation has on mite infestations, (ii) assess if mites locate in a particular band height of hazelnut plants; and (iii) assess the overall field infestation over the years. This study showed that not-irrigated plants and plants irrigated by underground pipe systems were similarly infested. Mites tend to locate in the middle band of the plant, namely from 1.5 to 3 m from the ground. The four-year survey showed an overall increasing infestation trend, with a peak in 2021 for irrigated plants and 2022 for not-irrigated. These results are a milestone for further exploration of the biology and ecology of this pest and to formulate ad hoc monitoring and control strategies as well. Full article

(This article belongs to the Special Issue Traditional and Innovative Pest and Disease Monitoring Strategies in Agroforestry)

► Show Figures

Figure 1

16 pages, 1308 KiB

Open AccessReview

Compatible Graft Establishment in Fruit Trees and Its Potential Markers

by Prakash Babu Adhikari, Qiang Xu and Michitaka Notaguchi

Agronomy 2022, 12(8), 1981; https://doi.org/10.3390/agronomy12081981 - 22 Aug 2022

Cited by 11 | Viewed by 4746

Abstract

Plant grafting is a maneuver humans learned from nature and has been practiced since ancient times. The technique has long been applied for efficient propagation as well as for the modification of the traits of interest, such as stress tolerance, tree size, and [...] Read more.

Plant grafting is a maneuver humans learned from nature and has been practiced since ancient times. The technique has long been applied for efficient propagation as well as for the modification of the traits of interest, such as stress tolerance, tree size, and fruit quality. Since grafting can enhance the environmental tolerance and disease resistance of a plant, its techniques are now used not only in tree species but also among vegetables. Despite such wide advantages of grafting, however, the potential cause behind a compatible graft establishment (scion-rootstock connection) is yet to be fully understood. As compared to succulent herbaceous plants, woody plants often take a longer time for the graft-take and the plants may exhibit incompatible/unsuccessful graft-establishment symptoms within a period ranging from months to years. In this review, we discuss factors involved in a successful/compatible graft establishment along with bottlenecks of our understanding and future perspectives in a simplified manner- particularly focusing on incompatible graft formation on fruit trees based on earlier studies in the field. Full article

(This article belongs to the Collection Scion-Rootstock Interaction in Horticultural Crops: Physiological and Agronomic Implications)

► Show Figures

Figure 1

Figure 1
A typical grafting (wedge) procedure. The scion and rootstock cut surfaces are properly aligned (a,b) and the union is covered with grafting tape (c) to support the union establishment. Depending on the graft partners, the normal graft establishment (d) in tree species could take weeks. (e) Incompatible combinations of graft partners with differential growth rates may exhibit swollen graft union. Full article ">Figure 2
Typical wound-induced clogging up pattern in trees. The first and second images in each sub-figure represent wounding type/condition and virtual sectioning (for better visualization of the clogging patterns), respectively: (a) clean horizontal cut leads to clogging up of pith followed by side-by tissues; (b) oblique cut leads to the formation of the clogged-up barrier in parallelly oblique position; and (c) when there is a branch present beneath the cut surface, the clogging up occurs in such a way that the nutrient and metabolite flow to and from the branch would not be hindered. Full article ">Figure 3
Basic anatomical states of graft establishment. (a–f) Typical transverse sections at the progressively healing graft union: (a) mechanically attached scion-rootstock combination with virtual sectioning at the graft joint; (b–f) magnified structure of a typical transverse section at the progressively healing graft union; (b) freshly attached scion and rootstock; (c) pectinaceous materials are secreted at the graft union and the attached graft partner surfaces are mechanically attached; the secreted pectinaceous materials, along with the cell debris forms a necrotic layer at the graft interface; (d) wound signal perception leads to the callus production at the graft interface, which thins out the necrotic barrier leading to the establishment of a callus bridge between two graft partners. The magnified image shows the proliferating callus cells before callus bridge formation at the graft interface; (e) a seamless connection is established at a compatible graft union; and (f) partially compatible graft unions often exhibit the remnants of the necrotic layer and/or aberrant vascular continuity. In severe incompatibility cases, the necrotic layer never disintegrates at all. i = cork and epidermis ii = cortex; iii = phloem; iv = vascular cambium; v = xylem; vi = protoxylem; vii = pith. Full article ">

20 pages, 4658 KiB

Open AccessArticle

Irrigation Method and Volume for Korla Fragrant Pear: Impact on Soil Water and Salinity, Yield, and Fruit Quality

by Yao Zhang, Hongguang Liu, Ping Gong, Xinlin He, Jiaxin Wang, Zonglan Wang and Jingrui Zhang

Agronomy 2022, 12(8), 1980; https://doi.org/10.3390/agronomy12081980 - 22 Aug 2022

Cited by 5 | Viewed by 2069

Abstract

A field study in an orchard of Korla fragrant pear tested three levels of irrigation (as varying proportions of evapotranspiration; namely, W1: 70% ET_C, W2: 85% ET_C, and W3: 100% ET_C) and four methods of applying such [...] Read more.

A field study in an orchard of Korla fragrant pear tested three levels of irrigation (as varying proportions of evapotranspiration; namely, W1: 70% ET_C, W2: 85% ET_C, and W3: 100% ET_C) and four methods of applying such irrigation; namely, F1: surface drip, F2: subsurface, F3: root zone infiltration, and CK: flood irrigation (as the control or check). The effects of the different treatments were evaluated in terms of plant growth (shoot length and leaf area), fruit yield and quality, and the distribution of water and salt in soil. For a given method of irrigation, soil moisture content, wet-front displacement, the length of new shoots, and leaf area under W3 were significantly higher than those under W1 and W2. The salt content under W3 was also significantly lower than that under W1 and W2, whereas the yield was significantly higher—by 5.89–13.85% compared to that under W2 and by 4.08–13.13% compared to that under W1. For a given volume of irrigation, yield, water-use efficiency, and fruit quality were significantly higher under F3 and F2 than those under F1. Soil water was more uniformly distributed and its content was significantly higher under F3 than the corresponding values under F1 or F2. The salt content of the root zone was the lowest under F3, and most of the soil salt was in soil layers deeper than 80 cm, but there was no significant difference between F3 and F2 (p < 0.05). There were also no significant differences in shoot length and leaf area among the three irrigation methods (F1, F2, and F3) (p < 0.05). Compared to that under F1, root zone infiltration under W1 was 3.61% greater, that under W2 was 6.58% greater, and that under W3 was 5.43% greater. The irrigation water-use efficiency and production factor efficiency for nitrogen under F3 and F2 were significantly higher than those under F1 (p < 0.05). Principal component analysis showed that the comprehensive score for fruit quality under different volumes of irrigation was the highest under W3, was intermediate under W2, and was the lowest under W1. The corresponding ranking of different irrigation methods was F2, F3, F1, and CK. Comprehensive analysis showed that yield, quality, and the efficiency of utilization of water and fertilizer were higher under the combination W3F3 than under any other combination—therefore, irrigation at 100% of evapotranspiration applied through root zone infiltration is recommended for Korla fragrant pear. The research results can provide a theoretical basis for the optimal use of water and for salt control in pear in Korla, Xinjiang. Full article

► Show Figures

Figure 1

Figure 1
Meteorological data of the experimental site. Full article ">Figure 2
The Korla fragrant pear planting model. surface drip (F1), subsurface drip (F2), and root zone infiltration (F3); 70% ETC (W1), 85% ETC (W2), and 100% ETC (W3); Flood irrigation at 100% ETC served as the check (CK) or control. Full article ">Figure 3
Three methods of irrigation. (a) Surface drip irrigation, a row consisting of two pipes was laid on both sides of the tree row, the drip head flow was 2 L/h, the distance between the drip heads was 50 cm, and the pipes were 40 cm away from the trees; (b) Subsurface drip irrigation, a row of two pipes was buried 20 cm below the surface, the drip head flow was 2 L/h, the distance between the drip heads was 50 cm, and the pipes were 40 cm away from the trees; (c) root zone infiltration irrigation, a pipe to supply water was laid at the bottom of the tree in each row. Holes to supply the water pipe were drilled every 50 cm, and polyethylene (PE) microtubes connected the holes to the seepage pipe. Two seepage pipes per plant were buried on either side, 30 cm from the rows of trees. Two rows of symmetrical water seepage holes with a diameter of 2 mm that were spaced 1 cm apart were drilled into the wall of the tube, which was buried 30 cm below the surface. A nozzle with a flow rate of 2 L/h connected by PE microtubes was placed inside the tube. Full article ">Figure 4
Locations of sampling points. Full article ">Figure 5
Distribution of soil moisture under different irrigation methods. Full article ">Figure 6
Changes in soil salinity (EC values) under different irrigation methods. Full article ">Figure 7
Changes in the desalination rate under different irrigation methods. Full article ">

27 pages, 7361 KiB

Open AccessArticle

Global Sensitivity Analysis of Key Parameters in the APSIMX-Sugarcane Model to Evaluate Nitrate Balance via Treed Gaussian Process

by R. H. K. Rathnappriya, Kazuhito Sakai, Ken Okamoto, Sho Kimura, Tomokazu Haraguchi, Tamotsu Nakandakari, Hideki Setouchi and W. B. M. A. C. Bandara

Agronomy 2022, 12(8), 1979; https://doi.org/10.3390/agronomy12081979 - 22 Aug 2022

Cited by 2 | Viewed by 2283

Abstract

Difficulties in direct monitoring of nitrate balance in agricultural fields reveal the importance of modeling and quantifying the affecting parameters on nitrate balance. We constructed meta-models for APSIMX-Sugarcane using the treed gaussian process and conducted a global sensitivity analysis for nitrate uptake and [...] Read more.

Difficulties in direct monitoring of nitrate balance in agricultural fields reveal the importance of modeling and quantifying the affecting parameters on nitrate balance. We constructed meta-models for APSIMX-Sugarcane using the treed gaussian process and conducted a global sensitivity analysis for nitrate uptake and leaching under three conditions: (1) bare land (BL) to examine the influence of soil hydraulic characteristics, (2) N-free treatment under radiation use efficiency (RUE) ranges (i) 1.2–1.8 [N-free(a)] and (ii) 1.8–2.5 [N-free(b)], and (3) urea conditions to examine the influence of plant growth. Generated meta-models showed good accuracy (for all conditions: R² > 0.70; NRMSE < 16%; AI > 0.90). The most influential parameters (sensitivity indices ≥ 0.02) were as follows: for leached NO₃−N in BL: the parameter rerated to saturated flow-proportion of water between saturation and field capacity (SWCON) of all soil layers; for NO₃⁻ uptake and leached NO₃−N in N-free(a) and urea: RUE of the phenological stage (PS) 3 (RUE3) and 4, tt_emerg_to_begcane, green_leaf_no, and y_n_conc_crit_leaf of PS 4 (NCL4); in N-free(b): RUE3, NCL4, and SWCON of soil layers 0–15 cm; 15–30 cm, which confirmed that influential parameters were depended on N-stress. The outcomes of this study are useful for enhancing the accuracy and efficiency of crop modeling. Full article

► Show Figures

Figure 1

23 pages, 4253 KiB

Open AccessArticle

Genome-Wide Identification of GASA Gene Family in Ten Cucurbitaceae Species and Expression Analysis in Cucumber

by Kaijing Zhang, Yuchao Hu, Dekun Yang, Congsheng Yan, Nanyang Li, Ziang Li, Martin Kagiki Njogu, Xing Wang and Li Jia

Agronomy 2022, 12(8), 1978; https://doi.org/10.3390/agronomy12081978 - 22 Aug 2022

Cited by 6 | Viewed by 2411

Abstract

Gibberellic acid-stimulated in Arabidopsis (GASA), a unique small molecular protein of plants, plays an essential role in plant growth and development. The GASA family genes have been identified and studied in many plants. However, the identification of GASA gene family in Cucurbitaceae species [...] Read more.

Gibberellic acid-stimulated in Arabidopsis (GASA), a unique small molecular protein of plants, plays an essential role in plant growth and development. The GASA family genes have been identified and studied in many plants. However, the identification of GASA gene family in Cucurbitaceae species has not been reported yet. Therefore, in this study, based on the available genome information on the Cucurbitaceae species, the GASA family genes in 10 Cucurbitaceae species including cucumber (Cucumis sativus), watermelon (Citrullus lanatus), melon (Cucumis melo), pumpkin (Cucurbita moschata), wax gourd (Benincasa hispida), sponge gourd (Luffa cylindrica), bottle gourd (Lagenaria siceraria), bitter gourd (Momordica charantia), chayote (Sechium edule), and snake gourd (Trichosanthes anguina) were identified with bioinformatics methods. To understand the molecular functions of GASA genes, the expression pattern analysis of cucumber GASA family genes in different tissues and stress responses were also analyzed. The results showed that a total of 114 GASA genes were identified in the 10 Cucurbitaceae species, which were divided into three subfamilies. Synteny analysis of GASA genes among cucumber, Arabidopsis and rice showed that nine cucumber GASA genes were colinear with 12 Arabidopsis GASA genes, and six cucumber GASA genes were colinear with six rice GASA genes. The cis-acting elements analysis implied that the cucumber GASA genes contained many cis-elements associated with stress and hormone response. Tissue-specific expression analysis of cucumber GASA family genes revealed that only the CsaV3_2G029490 gene was lowly or not expressed in all tissues, the CsaV3_3G041480 gene was highly expressed in all tissues, and the other seven GASA genes showed tissue-specific expression patterns. Furthermore, nine cucumber GASA family genes exhibited different degrees of regulatory response under GA, abiotic and biotic stresses. Two cucumber GASA genes, CsaV3_3G042060 and CsaV3_3G041480, were differentially expressed under multiple biotic and abiotic stresses, which indicated that these two GASA genes play important roles in the growth and development of cucumber. Full article

► Show Figures

Figure 1

11 pages, 31270 KiB

Open AccessArticle

The Solanum torvum Transcription Factor StoWRKY6 Mediates Resistance against Verticillium Wilt

by Yu Zhang, Lei Shen, Liangjun Li and Xu Yang

Agronomy 2022, 12(8), 1977; https://doi.org/10.3390/agronomy12081977 - 22 Aug 2022

Cited by 1 | Viewed by 1747

Abstract

WRKY is a transcription factor family that has attracted much attention in recent studies of plant disease resistance, but there are few reports in the study of eggplant resistance to Verticillium wilt. Here, we retrieved an up-regulated WRKY transcription factor, StoWRKY6, from [...] Read more.

WRKY is a transcription factor family that has attracted much attention in recent studies of plant disease resistance, but there are few reports in the study of eggplant resistance to Verticillium wilt. Here, we retrieved an up-regulated WRKY transcription factor, StoWRKY6, from the transcriptome sequencing data of Solanum torvum response to Verticillium dahliae infection. Phylogenetic analyses revealed the highest homology species of StoWRKY6 in the WRKY family is Solanum melongena. Based on the quantitative real-time PCR analysis, StoWRKY6 was highly expressed in the roots but barely expressed in the leaves. Transient expressions of StoWRKY6 in Nicotiana benthamiana showed a nuclear localization. A virus-mediated gene silencing experiment indicated that the silencing of StoWRKY6 reduced the resistance to Verticillium wilt in Solanum torvum. To further verify the immune response function, we introduced StoWRKY6 into Nicotiana benthamiana using transient transformation technology and found obvious spots under UV light. In summary, these results showed that StoWRKY6 played an important role in the resistance to Verticillium wilt of Solanum torvum, which may function mainly by inducing an immune response. Our study provided strong evidence for the mechanism of eggplant resistance to Verticillium wilt and laid a foundation for the potential molecular breeding of eggplant disease resistance. Full article

(This article belongs to the Special Issue Cultivation Physiology, Molecular Biology and Molecular Breeding of Solanaceae)

► Show Figures

Figure 1

Figure 1
Sequence alignment and phylogenetic tree analysis of StoWRKY6 with other plant WRKY proteins. (A) Analysis of the core conservative domain of StoWRKY6. (B) Alignment of StoWRKY6 with SmWRKY6, CaWRKY31, SlWRKW31, SlWRKY6, NtWRKY6, SlWRKY6, CarWRKY31, InWRKY31, GhWRKY31, AtWRKY6, and OsWRKY6. (C) Phylogenetic tree analysis of StoWRKY6 with other plant WRKY proteins. The phylogenetic tree was constructed by the neighbor-joining method using the MEGA program (version 6.05). (D) Analysis of the StoWRKY6 promoter region. Full article ">Figure 2
Subcellular localization of StoWRKY6 when transiently expressed in N. benthamiana leaves. The GFP-StoWRKY6 and GFP4 constructs were transferred into N. benthamiana leaves separately through agro-infiltration and the green fluorescence of the GFP4 was observed under confocal laser microscopy. Bar = 40 µM. Full article ">Figure 3
Tissue-specific expression and expression of StoWRKY6 in response to Verticillium dahliae infection. (a) Tissue-specific expression of StoWRKY6 in root, stem, and leaf. (b) Expression patterns of StoWRKY6 in response to Verticillium dahliae inoculation. The leaves were collected at 0, 12, 24, 36, 48, and 72 hpi, respectively. Different lowercase letters indicate significant differences based on the Fisher’s protected LSD test (p < 0.05). Full article ">Figure 4
Silencing of StoWRKY6 seriously compromises Verticillium wilt resistance in Solanum torvum. (a) PDS as a visual marker for silencing efficiency. (b) Relative expression level in the control and StoWRKY6 silenced plants 15 d after manual infiltration. (c) Disease symptoms induced by V. dahlia on the control and StoWRKY6 silenced plants at 25 dpi. (d) The relative expression level of V. dahlia in the control and StoWRKY6 silenced plants at 25 dpi. (e) Recovery test of the pathogen from stem segments of StoWRKY6 silenced plants. (f) Detection of pathogenic bacteria in stems by qRT-PCR. Different lowercase letters indicate significant differences based on the Fisher’s protected LSD test (p < 0.05). Full article ">Figure 5
StoWRKY6 stimulated tobacco anaphylactic reaction. (A) Lesion phenotype of N.benthamiana leaves infection with Verticillium dahliae. (B) Electrical conductivity of tobacco leaves at 24 h and 48 h after transient expression of StoWRKY6. (C) Relative expression of StoWRKY6. (D) Relative expression of disease resistance-related genes. Different lowercase letters indicate significant differences based on the Fisher’s protected LSD test (p < 0.05). Full article ">

18 pages, 6592 KiB

Open AccessArticle

Genome-Wide Identification of Long Non-Coding RNAs in Pearl Millet (Pennisetum glaucum (L.)) Genotype Subjected to Drought Stress

by Baibhav Kumar, Animesh Kumar, Sarika Jaiswal, Mir Asif Iquebal, Ulavappa B. Angadi, Rukam S. Tomar, Anil Rai and Dinesh Kumar

Agronomy 2022, 12(8), 1976; https://doi.org/10.3390/agronomy12081976 - 22 Aug 2022

Cited by 2 | Viewed by 2667

Abstract

Pearl millet (Pennisetum glaucum L.) is affected by drought stress, affecting crop productivity and survival. Long non-coding RNAs (lncRNAs) are reported to play a vital role in the response to drought stress. LncRNAs represent a major part of non-protein coding RNAs and [...] Read more.

Pearl millet (Pennisetum glaucum L.) is affected by drought stress, affecting crop productivity and survival. Long non-coding RNAs (lncRNAs) are reported to play a vital role in the response to drought stress. LncRNAs represent a major part of non-protein coding RNAs and are present prevalently. These are involved in various biological processes, which may functionally act as RNA rather than getting transcribed as protein. We targeted genome-wide identification of lncRNAs in pearl millet from root and leaf tissues subjected to drought stress. A total of 879 lncRNAs were identified, out of which 209 (leaf control, root control), 198 (leaf treated, root treated), 115 (leaf control, leaf treated) and 194 (root control, root treated) were differentially expressed. Two lncRNAs were found as potential target mimics of three miRNAs from the miRBase database. Gene ontology study revealed that drought-responsive lncRNAs are involved in biological processes like ‘metabolic process’ and ‘cellular process’, molecular functions like ‘binding’ and ‘catalytic activities’ and cellular components like ‘cell’, ‘cell part’ and ‘membrane part’. LncRNA-miRNA-mRNA network shows that it plays a vital role in the stress-responsive mechanism through their activities in hormone signal transduction, response to stress, response to auxin and transcription factor activity. Only four lncRNAs were found to get a match with the lncRNAs present in the plant lncRNA database CANTATAdb, which shows its poorly conserved nature among species. This information has been cataloged in the pearl millet drought-responsive long non-coding RNA database (PMDlncRDB). The discovered lncRNAs can be used in the improvement of important traits, as well as CISPR-Cas technology, in the editing of ncRNAs in plants for trait improvement. Such a study will increase our understanding of the expression behavior of lncRNAs, as well as its underlying mechanisms under drought stress in pearl millet. Full article

(This article belongs to the Special Issue Improvement of Crops: Current Status and Future Prospects)

► Show Figures

Figure 1

23 pages, 1942 KiB

Open AccessArticle

Seed Soaking with Sodium Selenate as a Biofortification Approach in Bread Wheat: Effects on Germination, Seedling Emergence, Biomass and Responses to Water Deficit

by Luís Rocha, Ermelinda Silva, Ivo Pavia, Helena Ferreira, Carlos Matos, José M. Osca, José Moutinho-Pereira and José Lima-Brito

Agronomy 2022, 12(8), 1975; https://doi.org/10.3390/agronomy12081975 - 21 Aug 2022

Cited by 5 | Viewed by 2592

Abstract

Selenium (Se) biofortification by seed treatments has been poorly explored in wheat due to the difficulties in establishing seed treatments without compromising plant productive traits. We investigated the effects of Se seed soaking as a pre-sowing treatment in bread wheat. Five soaking periods [...] Read more.

Selenium (Se) biofortification by seed treatments has been poorly explored in wheat due to the difficulties in establishing seed treatments without compromising plant productive traits. We investigated the effects of Se seed soaking as a pre-sowing treatment in bread wheat. Five soaking periods and six Se concentrations were assessed on germination and seedling traits and compared to unsoaked seeds. Twelve hours of soaking was found beneficial for most tested Se concentrations. Then, we evaluated the effects of untreated, 0, 2.5 and 25 mM Se in 12 h seed soaking treatments along the wheat crop cycle under water-deficit (WD) and well-watered (WW) conditions in a pot experiment. Our results evidenced that 12 h of 2.5 mM Se soaking did not affect the germination percentage, and speed-up seedling emergence resulted in a considerable Se seed uptake. These plants also displayed enhanced antioxidant capacity and vegetative biomass accumulation, especially under WD. The treatment with 25 mM of Se negatively affected aerial biomass, suggesting potential toxicity. Physiological responses of Se-treated plants remained unchanged, as well as grain traits. Altogether, we propose that 12 h soaking with 2.5 mM Se is a promissory pre-sowing approach to enrich bread wheat grain and straw, particularly under water-limited environments. Full article

(This article belongs to the Special Issue Effective Methods for Improving Seed Germination and Seed Quality)

► Show Figures

Figure 1

Figure 1
Timeline of the field trial. Full article ">Figure 2
Germinated seeds (n = 45) (a), electrolyte leakage of seed membrane (n = 15) (b) and root length sum from the three major roots (n = 45) (c), forty-eight hours after sowing. Five soaking periods (SP = 0, 4, 9, 12 and 24 h) and six concentrations of sodium selenate (S = 0, 0.25, 0.5, 2.5, 5 and 25 mM) were studied. Values are mean ± standard error. Two-away ANOVA p-values for SP, S and interaction SP × S were shown for each parameter. Complementary information on statistical significance is available in <a href="#app1-agronomy-12-01975" class="html-app">Supplementary Table S1</a>. Full article ">Figure 3
Selenium contents presented in seeds after 12 h of soaking with 0, 0.25, 0.5, 2.5, 5 and 25 mM of Na2SeO4. Values are means ± standard errors (n = 5). Different letters demonstrate significant differences (p < 0.05). Full article ">Figure 4
Percentage of seedlings with visible coleoptiles at 12, 18 and 24 days after sowing (DAS). Values are means ± standard errors (n = 80). Different letters demonstrate significant differences (p < 0.05). Full article ">Figure 5
Seedling height (a), leaves number (b), total leaves length (c) and tillers number (d) of wheat seedlings for the four Se soaking treatments (SP) during the first 56 days after sowing (DAS). Values are means ± standard errors (n = 80). Two-away ANOVA p-values for DAS, S and interaction DAS × S were shown for each parameter. Complementary information is shown in <a href="#app1-agronomy-12-01975" class="html-app">Supplementary Table S2</a>. Full article ">Figure 6
Chlorophyll a (Chl a)—(a); chlorophyll b (Chl b)—(b); chlorophyll a + b (Chl a + b)—(c); chlorophyll ratio (Chl a/Chl b)—(d); carotenoids (car)—(e) and chlorophyll/carotenoids ratio (Chl/Car)—(f) from wheat plants expressed per unit of dry weight (DW). Two water treatments (W) and four soaking treatments (S) were studied. Values are means ± SE (n = 12). Different letters indicate statistically significant differences (p < 0.05). Full article ">Figure 7
Total phenols—TPC (a); total flavonoids—TFC (b); ortho-diphenols—OD (c); ABTS+ (d); total soluble sugars—TSS (e) and total soluble proteins—TSP (f); among two water regimes and four soaking treatments (untreated, 0, 2.5, and 25 mM). Values are means ± SE of DW (n = 12). Different letters indicate statistically significant differences (p < 0.05). Full article ">

21 pages, 2748 KiB

Open AccessEditor’s ChoiceReview

Effects of Living Grass Mulch on Soil Properties and Assessment of Soil Quality in Chinese Apple Orchards: A Meta-Analysis

by Wenzheng Tang, Haosheng Yang, Wene Wang, Chunxia Wang, Yaoyue Pang, Dianyu Chen and Xiaotao Hu

Agronomy 2022, 12(8), 1974; https://doi.org/10.3390/agronomy12081974 - 21 Aug 2022

Cited by 15 | Viewed by 3218

Abstract

Soil degradation has exacerbated the gap between crop yield and increasing food demands, and unreasonable field management is one of the main reasons for soil degradation. As a classic orchard soil management mode, living grass mulch can effectively change the hydrothermal environment and [...] Read more.

Soil degradation has exacerbated the gap between crop yield and increasing food demands, and unreasonable field management is one of the main reasons for soil degradation. As a classic orchard soil management mode, living grass mulch can effectively change the hydrothermal environment and soil physicochemical properties of the ‘soil–vegetation–atmosphere’ microclimate of apple orchards. However, these improvement effects are mainly affected by climatic conditions, mulch methods, vegetation varieties and continuous grass-growing years. To evaluate the different effects of living grass mulch and the main influencing factors on soil physicochemical properties of apple orchards in China, in this study, we conducted a meta-analysis using data from 53 peer-reviewed publications to carry out soil quality assessment. The results showed that compared with clear tillage, continuous living grass mulch in apple orchards could improve soil function and performance by about 56% and increase soil enzyme activities by 10–120%, on average, whereas the soil organic matter under the effect of artificial grass and natural grass significantly increased by 29.6% and 14.6%, respectively. Artificial grass in temperate and warm, temperate, semi-humid climate regions had a greater overall improvement effect on the soil physicochemical environment than natural grass. Clover was found to be the most suitable for planting in apple orchards in temperate, semi-humid climate regions, whereas both clover and ryegrass were the best choices in warm, temperate, semi-humid climate regions. The interaction effects of different soil physicochemical properties in apple orchards in warm, temperate, semi-humid climate regions were greater than those in warm, temperate, arid climates and temperate, semi-humid climate regions. The response sensitivity of soil organic matter, organic carbon, urease, catalase, sucrose and cellulase to the living grass mulch effect of apple orchards was greater than that of other soil properties. Full article

► Show Figures

Figure 1

Figure 1
The overall effects of living grass mulch on soil physicochemical properties of apple orchards in China. Weighted means and their 95% confidence intervals of the effect sizes are given. The numbers on the right side of the confidence intervals represent the sample sizes. SBD: soil bulk density; STP: soil total porosity; SPH: soil pH; SWC: soil water content; SOM: soil organic matter; SOC: soil organic carbon; TN: soil total nitrogen; TP: soil total phosphorus; TK: soil total potassium; AN: soil available nitrogen; AP: soil available phosphorus; AK: soil available potassium. Full article ">Figure 2
Effects of mulch methods on soil physicochemical properties of apple orchards in China. The circles and squares represent artificial grass and natural grass, respectively. Weighted means and their 95% confidence intervals of the effect sizes are given. The numbers on the right side of the confidence intervals represent the sample sizes. SBD: soil bulk density; STP: soil total porosity; SPH: soil pH; SWC: soil water content; SOM: soil organic matter; SOC: soil organic carbon; TN: soil total nitrogen; TP: soil total phosphorus; TK: soil total potassium; AN: soil available nitrogen; AP: soil available phosphorus; AK: soil available potassium. Full article ">Figure 3
Effects of continuous grass-growing years on soil physicochemical properties of apple orchards in China. The circles represent the initial stage (<3 years), the squares represent the mid-term (3–5 years) and the triangles represent the long-term (>5 years). Weighted means and their 95% confidence intervals of the effect sizes are given. The numbers on the right side of the confidence intervals represent the sample sizes. SBD: soil bulk density; STP: soil total porosity, SPH: soil pH; SWC: soil water content; SOM: soil organic matter; SOC: soil organic carbon; TN: soil total nitrogen; TP: soil total phosphorus; TK: soil total potassium; AN: soil available nitrogen; AP: soil available phosphorus; AK: soil available potassium. Full article ">Figure 4
Response of soil physicochemical properties to different influencing factors for apple orchards with living grass mulch according to climate region. (a) Mulch methods. (b) Continuous grass-growing years. (c) Grass varieties. Medium green, orange-red, medium blue and cranberry colors represent warm, temperate semi-humid; warm, temperate arid; temperate, semi-humid; and temperate, semi-arid climate zones, respectively. Weighted means and their 95% confidence intervals of the effect sizes are given. The numbers at the top of the confidence intervals represent the sample sizes. SBD: soil bulk density; STP: soil total porosity, SPH: soil pH; SWC: soil water content; SOM: soil organic matter; SOC: soil organic carbon; TN: soil total nitrogen; TP: soil total phosphorus; TK: soil total potassium; AN: soil available nitrogen; AP: soil available phosphorus; AK: soil available potassium. Full article ">Figure 5
Correlation analysis among different soil characteristics. (a) the whole China region; (b) the warm temperature semid-humid climate region; (c) the temperature semi-humid climate region; (d) the warm temperature arid climate region. SBD: soil bulk density; STP: soil total porosity, SPH: soil pH; SWC: soil water content; SOM: soil organic matter; SOC: soil organic carbon; TN: soil total nitrogen; TP: soil total phosphorus; TK: soil total potassium; AN: soil available nitrogen; AP: soil available phosphorus; AK: soil available potassium. Full article ">Figure 6
The soil quality index area (SQI-area) approach suitable for unifying evaluation of any number of soil parameters and to compare various SQI methods. (a) the whole China region; (b) the warm temperature semid-humid climate region. A decrease in the area on the radar plot between a non-degraded and a degraded soil is necessary. The ratio between the SQI area of non-degraded and degraded soils is independent of the number of parameters and the weightings involved in the calculation of the area. SBD: soil bulk density; STP: soil total porosity, SPH: soil pH; SWC: soil water content; SOM: soil organic matter; SOC: soil organic carbon; TN: soil total nitrogen; TP: soil total phosphorus; TK: soil total potassium; AN: soil available nitrogen; AP: soil available phosphorus; AK: soil available potassium; SU: soil urease activity; SC: soil catalase activity; SS: soil sucrase activity; SE: soil cellulase activity. Full article ">

17 pages, 1716 KiB

Open AccessArticle

At Which Spatial Scale Does Crop Diversity Enhance Natural Enemy Populations and Pest Control? An Experiment in a Mosaic Cropping System

by Coline C. Jaworski, Eva Thomine, Adrien Rusch, Anne-Violette Lavoir, Chunli Xiu, Di Ning, Yanhui Lu, Su Wang and Nicolas Desneux

Agronomy 2022, 12(8), 1973; https://doi.org/10.3390/agronomy12081973 - 21 Aug 2022

Cited by 5 | Viewed by 2416

Abstract

The importance of plant richness to enhance the presence, biodiversity and efficiency of natural enemies in agricultural systems has largely been studied and demonstrated these last decades. Planting and preserving non-crop plants or manipulating crop richness in fields are practices that have proven [...] Read more.

The importance of plant richness to enhance the presence, biodiversity and efficiency of natural enemies in agricultural systems has largely been studied and demonstrated these last decades. Planting and preserving non-crop plants or manipulating crop richness in fields are practices that have proven their efficiency. However, the impact of crop-richness continuity in space and time on pests and natural enemies at a landscape scale remains poorly studied. In a two-year study, we assessed the effect of crop richness (single crop vs. multiple crops) on pest and natural enemy abundance and spillover in a field experiment in north-east China. Overall, we found crop diversity had a limited impact on pest and natural enemy abundance at the spatial scale tested (0.025 vs. 0.2 ha). The total pest and natural enemy abundances were not different between single-crop and multi-crop plots in either year, and the community composition at the functional group level was mostly determined by the crop but not crop diversity. However, we found that crop diversity influenced the numeric response of ladybirds to aphids in wheat; their negative response (higher abundance where aphid abundance was lower, suggesting predation) was attenuated in multi-crop plots (no correlation of aphid and ladybird abundance, suggesting the use of alternative resources). This pattern was not found in maize. Finally, crop succession enhanced the spillover of ladybirds from wheat and maize to cotton plots but with limited benefits for aphid control. Because of these limited impacts, we hypothesized that crop diversity may benefit natural enemy populations and enhance pest control at larger spatial scales; while we found similar abundances of ladybirds between our small (0.025–0.2 ha) plots and in large (2 ha) close-by cotton fields, aphid abundances were more than ten times higher in large cotton fields. Our study highlights the need to accurately estimate the spatial scale at which crop biodiversity may benefit pest control, in relation to the ecology of the target pest and natural enemies. Full article

(This article belongs to the Special Issue Ecological Management of Pests)

► Show Figures

Figure 1

Figure 1
Mean total abundance (mean total number per five plant ± SEM over time) of pests (A,C) and natural enemies (B,D) in the different crops and crop diversity treatments in 2017 (A,B) and 2018 (B,D). The proportions of cereal specialists (“spe.”) and generalists (“gen.”) pests in 2018 are shown with grey and green bars, respectively. Neither crop diversity nor crop (or pest diet breadth in 2018) significantly affected total abundance (<a href="#agronomy-12-01973-t001" class="html-table">Table 1</a>). Full article ">Figure 2
Communities of arthropod visitors (both pests and natural enemies) sampled over the 2017 (A) and 2018 (B) sampling seasons in each subplot: relative abundances of functional groups (total number of individual of each functional group sampled per subplot over time). Constrained correspondence analyses across crop-diversity treatments, crop types and arthropod functional groups. Only crop type (2017: Ca: cabbage, Ma: maize, To: tomato; 2018: Ca: cabbage, Co: cotton, Ma: maize, Wh: wheat) significantly affected the community composition as shown by the separation in distinct clouds of points in the two-dimensional space (<a href="#agronomy-12-01973-t002" class="html-table">Table 2</a>). Full article ">Figure 3
Regression coefficient estimates ± SE (thick bars) ± 95% confidence interval (thin bars) between ladybird and aphid abundances in maize (dark green) and wheat (light green) and between aphid parasitoid and aphid abundances in all crops (blue: ‘Ca+Co+Wh’: cabbage, cotton, and wheat), in single-crop plots (S) and multi-crop plots (M) (or all plots ‘S+M’). An estimate significantly above zero shows a positive correlation between aphids and its natural enemies, while an estimate significantly below zero shows a negative correlation between aphids and its natural enemies. A significant impact of crop diversity would cause estimate ranges to not overlap (here, only the estimates for ladybirds in wheat show a marginally significant impact of crop diversity with disjunct SE ranges). The crop diversity and crop did not affect the correlation between aphid parasitoids and aphids (<a href="#agronomy-12-01973-t003" class="html-table">Table 3</a>), hence only one regression coefficient is shown. Full article ">Figure 4
Mean ladybird (A,B) and aphid (C,D) abundances (number per five plants ± SEM) in maize (A,C) and cotton (B,D) subplots through time in each crop diversity treatment in 2018 (N = 5 for each date). The star shows a significant difference in the abundance of ladybirds in cotton subplots in single- vs. multi-crop plots during the first two weeks (χ21 = 7.56, p = 0.0059, GLMM with negative binomial distribution). Full article ">Figure 5
Impact of the spatial scale of crop diversity in our experiments versus nearby 2 ha fields on the abundance of (A) ladybirds and (B) aphids; ‘6 crops’/‘4 crops’: 2017 crop-diversity treatments (subplot size 0.025 ha); ‘multi’/‘single’: 2018 crop-diversity treatments (‘multi’: 0.025 ha; ‘single’: 0.2 ha); ‘2 ha’: large cotton fields nearby. ‘*’ shows significant differences (p < 0.001). ‘#’ Mean abundance ± SE of aphids in large fields in 2018 was divided by 10 for graphical aesthetics and clarity. Full article ">

20 pages, 23328 KiB

Open AccessArticle

Remote Sensing-Based Evaluation of Heat Stress Damage on Paddy Rice Using NDVI and PRI Measured at Leaf and Canopy Scales

by Jae-Hyun Ryu, Dohyeok Oh, Jonghan Ko, Han-Yong Kim, Jong-Min Yeom and Jaeil Cho

Agronomy 2022, 12(8), 1972; https://doi.org/10.3390/agronomy12081972 - 20 Aug 2022

Cited by 5 | Viewed by 2796

Abstract

Extremely high air temperature at the heading stage of paddy rice causes a yield reduction due to the increasing spikelet sterility. Quantifying the damage to crops caused by high temperatures can lead to more accurate estimates of crop yields. The remote sensing technique [...] Read more.

Extremely high air temperature at the heading stage of paddy rice causes a yield reduction due to the increasing spikelet sterility. Quantifying the damage to crops caused by high temperatures can lead to more accurate estimates of crop yields. The remote sensing technique evaluates crop conditions indirectly but provides information related to crop physiology, growth, and yield. In this study, we aim to assess the crop damage caused by heat stress in paddy rice examined under elevated air temperatures in a temperature gradient field chamber from 2016 to 2019, using remote-sensed vegetation indices. A leaf-spectrometer, field-spectrometers, and a multi-spectral camera were used to monitor the conditions of paddy rice. Although, in the leaf- and canopy-scales, the values of normalized difference vegetation index (NDVI) and photochemical reflectance index (PRI) decreased after the heading of rice under normal conditions, the decreasing sensitivity of NDVI and PRI was different depending on the degree of physiological heat stress by high temperature conditions. The NDVI after the heading under extremely high air temperature was not dropped and remained the value before heading. The PRI decreased at all air temperature conditions after the heading; the PRI of the plot exposed to the elevated air temperature was higher than that under ambient air temperature. Further, the relative change in NDVI and PRI after the heading exhibited a strong relationship with the ripening ratio of paddy rice, which is the variable related to crop yield. These remote-sensing results aid in evaluating the crop damage caused by heat stress using vegetation indices. Full article

(This article belongs to the Special Issue Advances in Field Spectroscopy in Agriculture)

► Show Figures

Figure 1

18 pages, 1920 KiB

Open AccessArticle

Chlorpyrifos Removal in an Artificially Contaminated Soil Using Novel Bacterial Strains and Cyclodextrin. Evaluation of Its Effectiveness by Ecotoxicity Studies

by Alba Lara-Moreno, Esmeralda Morillo, Francisco Merchán, Fernando Madrid and Jaime Villaverde

Agronomy 2022, 12(8), 1971; https://doi.org/10.3390/agronomy12081971 - 20 Aug 2022

Cited by 11 | Viewed by 2260

Abstract

The removal of chlorpyrifos (CLP) from the environment is a matter of general interest, because it is one of the most widely used insecticides in the world but presents a high toxicity and persistence in the environment. Biological strategies are considered as a [...] Read more.

The removal of chlorpyrifos (CLP) from the environment is a matter of general interest, because it is one of the most widely used insecticides in the world but presents a high toxicity and persistence in the environment. Biological strategies are considered as a good option to remediate different environmental compartments. Assisted natural attenuation was used to find the ability of different kinds of soils to mineralise CLP. In this way, two soils showed the capacity to degrade CLP (R and LL up to 47.3% and 61.4% after 100 d, respectively). Thus, two CLP-degrading strains, Bacillus megaterium CCLP1 and Bacillus safensis CCLP2 were isolated from them, showing the capacity to degrade up to 99.1 and 98.9% of CLP in a solution with an initial concentration of 10 mg L⁻¹ after 60 d. Different strategies were considered for increasing the effectiveness of soil bioremediation: (i) biostimulation, using a nutrients solution (NS); (ii) bioaugmentation, using B. megaterium CCLP1 or B. safensis CCLP2; (iii) bioavailability enhancement, using randomly methylated β-cyclodextrin (RAMEB), a biodegradable compound. When bioaugmentation and RAMEB were jointly inoculated and applied, the best biodegradation results were achieved (around 70%). At the end of the biodegradation assay, a toxicity test was used to check the final state of the bioremediated soil, observing that when the degrading strains studied were individually inoculated into the soil, the toxicity was reduced to undetectable levels. Full article

(This article belongs to the Special Issue Impact of Agrochemicals on Soil)

► Show Figures

Figure 1

11 pages, 5903 KiB

Open AccessEditor’s ChoiceArticle

Vernacular Names and Genetics of Cultivated Coffee (Coffea arabica) in Yemen

by Christophe Montagnon, Veronica Rossi, Carolina Guercio and Faris Sheibani

Agronomy 2022, 12(8), 1970; https://doi.org/10.3390/agronomy12081970 - 20 Aug 2022

Cited by 7 | Viewed by 6010

Abstract

While Ethiopia and South Sudan are the native habitats for Coffea arabica, Yemen is considered an important domestication center for this coffee species as most Arabica coffee grown around the world can be traced back to Yemen. Furthermore, climatic conditions in Yemen [...] Read more.

While Ethiopia and South Sudan are the native habitats for Coffea arabica, Yemen is considered an important domestication center for this coffee species as most Arabica coffee grown around the world can be traced back to Yemen. Furthermore, climatic conditions in Yemen are hot and extremely dry. As such, Yemeni coffee trees likely have genetic merits with respect to climate resilience. However, until recently, very little was known about the genetic landscape of Yemeni coffee. The Yemeni coffee sector identifies coffee trees according to numerous vernacular names such as Udaini, Tufahi or Dawairi. However, the geographical landscape of these names and their correlation with the genetic background of the coffee trees have never been explored. In this study, we investigated the geographic occurrence of vernacular names in 148 coffee farms across the main coffee areas of Yemen. Then, we used microsatellite markers to genotype 88 coffee trees whose vernacular name was ascertained by farmers. We find a clear geographical pattern for the use of vernacular coffee names. However, the vernacular names showed no significant association with genetics. Our results support the need for a robust description of different coffee types in Yemen based on their genetic background for the benefit of Yemeni farmers. Full article

(This article belongs to the Section Crop Breeding and Genetics)

► Show Figures

Figure 1

Figure 1
Map of Yemen and coffee-growing regions covered by the study. Full article ">Figure 2
List and frequency of vernacular coffee names mentioned on 148 coffee farms in Yemen. Full article ">Figure 3
Share of vernacular coffee names mentioned on 148 farms from different governates in Yemen. In each cell (=governorate), the area for each name is proportional to its frequency. The sum of frequencies in each governorate is equal to 1. Full article ">Figure 4
Share of coffee genetic group amongst samples with the same vernacular name (left) and share of vernacular names for each genetic group (right). The sum of frequencies in each cell is equal to 1. Full article ">Figure 5
Representation of 88 coffee samples on the first two components of the PcoA based on their SSR profile. The first row includes all the samples, and subsequent rows show samples of each vernacular name separately. The color of each point corresponds to the different genetic groups. Full article ">Figure 6
Genetic make-up of 88 coffee samples along with their vernacular name and the governorate of origin. Full article ">

16 pages, 2782 KiB

Open AccessArticle

Seed Characteristics Affect Low-Temperature Stress Tolerance Performance of Rapeseed (Brassica napus L.) during Seed Germination and Seedling Emergence Stages

by Tao Luo, Ziwei Sheng, Chunni Zhang, Qin Li, Xiaoyan Liu, Zhaojie Qu and Zhenghua Xu

Agronomy 2022, 12(8), 1969; https://doi.org/10.3390/agronomy12081969 - 20 Aug 2022

Cited by 6 | Viewed by 2196

Abstract

Screening and breeding elite varieties with rapid germination and uniform seedling emergence under low temperature is an effective strategy to deal with the cold climate occurring under late sowing conditions in the Yangtze River basin. This study focused on the performance of seven [...] Read more.

Screening and breeding elite varieties with rapid germination and uniform seedling emergence under low temperature is an effective strategy to deal with the cold climate occurring under late sowing conditions in the Yangtze River basin. This study focused on the performance of seven functional traits, including percentage of germination, percentage of emergence, mean germination time, mean emergence time, total seedling length, total dry weight, and seedling vigor index of 436 natural rapeseed populations under normal-temperature (25/20 °C) and low-temperature (15/10 °C) conditions. Furthermore, ten genotypes were screened to verify their low-temperature tolerance based on cultivar traits in a pot experiment. The results show that the germination- and emergence-related functional traits of rapeseed genotypes exhibit rich genotypic diversity in response to low-temperature stress; the variation among these traits ranged from 1–25% under normal-temperature and 10–49% under low-temperature conditions. Variation in seed characteristics also affected the capacity for low-temperature tolerance in the process of seed germination and seedling emergence, and could explain 22% of the total variance for low-temperature stress tolerance indices. There existed high correlations between the stress tolerance index of total dry weight (STI_TDW) and thousand-seed weight, and between the stress tolerance index of emergence percentage (STI_PE) and oil content. The contents of erucic acid, glucosinolate, and eicosenoic acid were positively correlated with the stress tolerance index of mean germination time (STI_MGT) and mean emergence time (STI_MET). The D-CRITIC (distance-based intercriteria correlation) weight method was selected in this experiment to calculate each variety’s comprehensive low-temperature stress tolerance index by integrating the standard deviation and distance correlation coefficient of each index. The genotypes with large comprehensive low-temperature stress tolerance index also had higher low-temperature stress tolerance index of biomass and yield in the pot experiment, indicating that the comprehensive low-temperature stress tolerance index has high reliability and applicability. This study could provide a theoretical basis for the utilization of low-temperature-tolerant germplasm resources, as well as a reference for the cold resistance and yield stability under late- and direct-sowing conditions of rapeseed in the Yangtze River basin and other similar environments around the world. Full article

(This article belongs to the Special Issue Abiotic Stress Tolerance in Brassica Species: From Molecular Laboratories to Field Trials)

► Show Figures

Figure 1

Figure 1
Dynamic changes of the average, maximum, and minimum temperatures under normal and late sowing conditions. Full article ">Figure 2
Frequency distribution of functional traits related to seed germination and seedling emergence under normal- (CK) and low-temperature (LT) conditions for 436 rapeseed lines. PG, percentage of germination; PE, percentage of emergence; MGT, mean germination time; MET, mean emergence time; TL, total seedling length; TDW, total dry weight; SVI, seedling vigor index. Full article ">Figure 3
The distributions and distance correlation coefficients of the seed germination- and seedling emergence-related low-temperature tolerance indices. STI_PG, low-temperature stress tolerance index of germination percentage; STI_PE, low-temperature stress tolerance index of emergence percentage; STI_MGT, low-temperature stress tolerance index of mean germination time; STI_MET, low-temperature stress tolerance index of mean emergence time; STI_TDW, low-temperature stress tolerance index of total dry weight; STI_TL, low-temperature stress tolerance index of total seedling length; STI_SVI, low-temperature stress tolerance index of seedling vigor index. Full article ">Figure 4
Comprehensive low-temperature stress tolerance index frequency distribution (A) and Shapiro–Wilk normality test outcome (B). Full article ">Figure 5
Schematic representations of a triplot-based redundancy analysis. Red arrows indicate explanatory variables, namely seed traits; blue arrows indicate the response variable, namely the low-temperature stress tolerance index related to seed germination and seedling emergence. The grey points represent genotype varieties. Full article ">Figure 6
Seedling emergence performance of rapeseed genotypes with high or low comprehensive low-temperature tolerance index under normal-temperature (normal sowing date) and low-temperature (late sowing date) conditions after 4 days of sowing in the pot experiment. Full article ">Figure 7
The agronomic performance under germination box trail and pot experiment of varieties with different low-temperature tolerance comprehensive scores. (A) Comparison of low-temperature STIs of seedling emergence between germination box and pot conditions; (B) relationship between comprehensive STIs in germination box and biomass-related low-temperature STIs in the pot experiment; (C) relationship between comprehensive STIs in germination box and seed yield-related low-temperature STIs in the pot experiment. Full article ">

20 pages, 4547 KiB

Open AccessArticle

Molecular Phylogenetic Analysis of Salt-Tolerance-Related Genes in Root-Nodule Bacteria Species Sinorhizobium meliloti

by Victoria Spartakovna Muntyan and Marina Lvovna Roumiantseva

Agronomy 2022, 12(8), 1968; https://doi.org/10.3390/agronomy12081968 - 20 Aug 2022

Cited by 4 | Viewed by 2314

Abstract

A molecular phylogenetic analysis of salt-tolerance-related genes was carried out using complete genome sequencing data available for 26 Sinorhizobium meliloti strains and for 25 bacterial strains belonging to 17 genera. It was revealed that the genes of the first and the second stages [...] Read more.

A molecular phylogenetic analysis of salt-tolerance-related genes was carried out using complete genome sequencing data available for 26 Sinorhizobium meliloti strains and for 25 bacterial strains belonging to 17 genera. It was revealed that the genes of the first and the second stages of the response to salt stress (aqpZ, trkH, and trkA, and betICBA) have copies of many of the above- indicated genes on pSymA. Data obtained can provide evidence that this replicon, known to be essential for nitrogen fixation rhizobia activity, also has a significant role in the formation of a stress-related gene pool. The closest putative phylogenetic relatives were identified for all 14 tested genes and these are the first insights into the evolutionary pathways for the formation of a stress-related gene pool in root nodule nitrogen-fixing bacteria. Full article

(This article belongs to the Special Issue Rhizobial Symbiosis in Crop Legumes: Molecular and Cellular Aspects)

► Show Figures

Figure 1

18 pages, 2289 KiB

Open AccessArticle

Vine Physiology, Yield Parameters and Berry Composition of Sangiovese Grape under Two Different Canopy Shapes and Irrigation Regimes

by Gabriele Valentini, Chiara Pastore, Gianluca Allegro, Riccardo Mazzoleni, Fabio Chinnici and Ilaria Filippetti

Agronomy 2022, 12(8), 1967; https://doi.org/10.3390/agronomy12081967 - 20 Aug 2022

Cited by 6 | Viewed by 2281

Abstract

Vitis vinifera L. adapts well to a scarce availability of water in the soil. However, in recent decades, the combination of thermal stress with prolonged water scarcity could have dramatic consequences on the vine’s physiological status. In this paper, we evaluated the effects [...] Read more.

Vitis vinifera L. adapts well to a scarce availability of water in the soil. However, in recent decades, the combination of thermal stress with prolonged water scarcity could have dramatic consequences on the vine’s physiological status. In this paper, we evaluated the effects of two canopy shapes and two irrigation regimes at veraison on vine physiology, yield parameters and grape composition through biochemical and molecular approaches. The water shortage strongly influenced the physiology of Sangiovese only when the stress was moderate to severe. Neither the water stress limited to veraison nor the canopy shape were able to influence the yield parameters and sugar content, and a strong induction of the expression of the genes involved in the biosynthesis of anthocyanins was recorded only in conditions of moderate-to-severe stress. This phenomenon led to an increase in the anthocyanin content in berry skins until the end of veraison. Conversely, no significant effects occurred in terms of biochemical and molecular performance after re-watering and at harvest. Though the shape of the canopy could play a role only under elevated temperature and prolonged drought, severe water stress can affect the vine physiology and berry ripening during the veraison stage. Full article

(This article belongs to the Special Issue How to Deal with the Grapevine Multiple Summer Stress through a Physiological, Biochemical, and Molecular Approach)

► Show Figures

Figure 1

Figure 1
Daily air temperature and relative humidity during the month of August in the 2018 (A) and 2019 (B) seasons. The duration of the water stress period is indicated by black double arrows. Full article ">Figure 2
Seasonal pattern of daily lysimeter transpiration in water-stress (WS) and well-watered (WW) vines during the stress period in the 2018 (A) and 2019 (B) seasons. Data are average of 8 vines ± SE. Within each day, an asterisk indicates a significant difference between the two water regimes as calculated by the Tukey test (p ≤ 0.05). Full article ">Figure 3
Evolution of total soluble solid content (°Brix) in Sangiovese berries sampled in closed (C) and V (V) canopy-shaped vines under normal water supply (WW) or water stress at veraison (WS) in 2018 (A) and 2019 (B) seasons. Error bars indicate the mean SE (n = 4). Means followed by different letters differ significantly, as calculated by Tukey test (p ≤ 0.05). The duration of the water stress period is indicated by black double arrows. Full article ">Figure 4
Evolution of total anthocyanin concentration (mg g-1 berry skin) in Sangiovese berries sampled in closed (C) and V (V) canopy-shaped vines under normal water supply (WW) or water stress at veraison (WS) in 2018 (A) and 2019 (B) seasons. Error bars indicate the mean SE (n = 4). Means followed by different letters differ significantly, as calculated by Tukey test (p ≤ 0.05). The duration of the water stress period is indicated by black double arrows. Full article ">Figure 5
Expression profiles of PAL1, DFR, LDOX, MYBA1 and UFGT genes in the skin of Sangiovese berries sampled in closed (C) and V (V) canopy shaped vines under normal water supply (WW) or water stress at veraison (WS) in 2018 (A,C,E,G,I) and 2019 (B,D,F,H,J) seasons respectively. Real time RT-PCR data are reported as mean normalized expression (MNE) values, obtained using actin and ubiquitin-1 as reference genes. Error bars indicate the mean SE (n = 4). Means followed by different letters differ significantly, as calculated by Tukey test (p ≤ 0.05). The duration of the water stress period is indicated by black double arrows. Full article ">

12 pages, 3035 KiB

Open AccessArticle

Diversity in Acidity between Core and Pulp of Asian Pear Fruit Is Mainly Regulated by the Collaborative Activity of PH8.1 and DIC2 Genes during Fruit Development

by Shariq Mahmood Alam, Dong-Hai Liu, Muhammad Ateeq, Han Han, Huan Chen, Muhammad Abbas Khan, Yin Luo, Xue-Ling Chen and Yong-Zhong Liu

Agronomy 2022, 12(8), 1966; https://doi.org/10.3390/agronomy12081966 - 20 Aug 2022

Cited by 1 | Viewed by 2356

Abstract

The pear (Pyrus pyrifolia) is an important accessory fruit in which the pear core is tarter than the pear pulp. However, the reason for the acidic core and diversity in the taste of the same fruit is not clear. In this [...] Read more.

The pear (Pyrus pyrifolia) is an important accessory fruit in which the pear core is tarter than the pear pulp. However, the reason for the acidic core and diversity in the taste of the same fruit is not clear. In this study, we observed that the citrate contents were three times higher in the core than in the pulp, while the malate content decreased along with fruit development and was significantly lower in the core than in the pulp at 110 days after flowering. Overall transcript levels for citrate-malate synthesis-related genes increased more in the pear core than the pulp at early fruit development, while degradation-related genes activity was nearly similar or non-significant between the core and pulp during fruit development. The lesser malate accumulation in the pear core compared to the pulp at 110 DAF was possibly due to the reduced activity of tDT2 gene. Regarding citrate accumulation, we identified five important p-type H⁺-ATPase genes in pear and found that the relative expression level of the PH8.1 gene was four-fold higher in the core than in the pulp during fruit development. Moreover, the expression level of di-carboxylate carrier gene 2 (DIC2) was constantly and significantly higher in the core than in the pulp. In addition, correlation analysis signified that the transcript levels of the two genes PH8.1 and DIC2 positively and significantly correlated with the citrate contents. These results suggested that the increased and collaborative activity of PH8.1 and DIC2 played a key role in the higher citrate accumulation in the core than the pulp, thus, with the help of molecular breeding tools, the citrate contents can be optimized in pear fruit for divers and improved fruit flavoring. Full article

(This article belongs to the Special Issue Omics Approaches and Applications in Fruit Crops Improvement)

► Show Figures

Figure 1

Figure 1
Comparison of fruit physical traits, total soluble solution (TSS), and titratable acidity (TA) between pear core and pulp during fruit development. (A) Pictorial view of pear fruit and identification of pear core and pear pulp. (B) Evaluation of TSS (°Brix) and TA (%) between core and pulp of pear fruit during development. (C) Organic acid contents between core and pulp of pear fruit. The asterisk denotes significant difference (p < 0.05) between core and pulp tissues of pear fruit; error bar determines ± SD of four replications. Full article ">Figure 2
Heatmap of relative mRNA level profiles for malate synthase- and degradation-related genes between core and pulp during fruit development. Maximum levels are denoted by red and minimum levels are denoted by yellow color boxes. Abbreviations: MS—Malate synthase; cMDH—cytosolic malate dehydrogenase; mMDH—mitochondrial malate dehydrogenase; ME—malic enzyme. Full article ">Figure 3
Heatmap of relative mRNA level profiles for citrate synthase- and degradation-related genes between core and pulp during fruit development. Maximum levels are denoted by red and minimum levels are denoted by yellow color boxes. Abbreviations: CS—Citrate synthase; ACL—ATP citrate lysase; ACO—aconitate hydrates. Full article ">Figure 4
Transcript comparison of di-carboxylate transporter genes for citrate and malate transport between pear core and pulp during pear fruit development. (A) Relative mRNA levels of genes related to di-carboxylate transporter (tDT), mitochondrial di-carboxylate carrier (DIC2), and di-carboxylate transporter (DIT2) in core and pulp. (B) Pearson correlation matrix between malate or citrate content and di-carboxylate transporter genes’ relative mRNA levels. The colored gradient legends represent coefficients of correlation r-values from +1.0 (dark green) to −1.0 (dark red). The asterisk denotes significant difference (p < 0.05); error bar determines ± SD of four replications. Full article ">Figure 5
Transcript comparison of aluminum-activated malate transporter genes (ALMTs) for citrate or malate accumulation between pear core and pulp during pear fruit development. (A) Relative mRNA levels of ALMT genes in core and pulp. (B) Pearson correlation matrix between malate or citrate content and ALMT genes’ relative mRNA levels. The colored gradient legends represent coefficients of correlation r-values from +1.0 (dark green) to −1.0 (dark red). The asterisk denotes significant difference (p < 0.05); error bar determines ± SD of four replications. Full article ">Figure 6
Transcript comparison of plasma membrane P3A-ATPases genes (PHs) for citrate or malate accumulation between pear core and pulp during pear fruit development. (A) Relative mRNA levels of PH genes in core and pulp. (B) Pearson correlation matrix between malate or citrate content and PH genes’ relative mRNA levels. The colored gradient legends represent coefficients of correlation r-values from +1.0 (dark green) to −1.0 (dark red). The asterisk denotes significant difference (p < 0.05); error bar determines ± SD of four replications. Full article ">

15 pages, 2553 KiB

Open AccessArticle

Machine Learning-Based Hyperspectral and RGB Discrimination of Three Polyphagous Fungi Species Grown on Culture Media

by Jan Piekarczyk, Andrzej Wójtowicz, Marek Wójtowicz, Jarosław Jasiewicz, Katarzyna Sadowska, Natalia Łukaszewska-Skrzypniak, Ilona Świerczyńska and Katarzyna Pieczul

Agronomy 2022, 12(8), 1965; https://doi.org/10.3390/agronomy12081965 - 20 Aug 2022

Cited by 2 | Viewed by 2223

Abstract

In this study, three fungi species (Botrytis cinerea, Rhizoctonia solani, Sclerotinia sclerotiorum) were discriminated using hyperspectral and red-green-blue (RGB) data and machine learning methods. The fungi were incubated at 25 °C for 10 days on potato dextrose agar in Petri dishes. [...] Read more.

In this study, three fungi species (Botrytis cinerea, Rhizoctonia solani, Sclerotinia sclerotiorum) were discriminated using hyperspectral and red-green-blue (RGB) data and machine learning methods. The fungi were incubated at 25 °C for 10 days on potato dextrose agar in Petri dishes. The Hyperspectral data were acquired using an ASD spectroradiometer, which measures reflectance with 3 and 10 nm bandwidths over the range 350–1000 nm and the range 1000–2500 nm, respectively. The RGB images were collected using a digital Canon 450D camera equipped with the DIGIC 3 processor. The research showed the possibility of distinguishing the analysed fungi species based on hyperspectral curves and RGB images and assessing this differentiation using machine learning statistical methods (extreme boosting machine with bootstrap simulation). The best results in analysed fungi discrimination based on hyperspectral data were achieved using the Principal Component Analysis method, in which the average values of recognition and accuracy for all three species were 0.96 and 0.93, respectively. The wavelengths of the shortwave infrared (SWIR) wavelength region appeared to be the most effective in distinguishing B. cinerea-R. solani and B. cinerea-S. sclerotiorum, while of the visible range (VIS) of electromagnetic spectrum in discrimination of R. solani-S. sclerotiorum. The hyperspectral reflectance data were strongly correlated with the intensity of the pixels in the visible range (R² = 0.894–0.984). The RGB images proved to be successfully used primarily for the identification of R. solani (recognition = 0.90, accuracy = 0.79) and S. sclerotiorum (recognition = 0.84, accuracy = 0.76). The greatest differences in the intensity of the pixels between B. cinerea and R. solani as well as R. solani and S. sclerotiorum occurred in the blue band and in distinguishing B. cinerea and S. sclerotiorum in the red band. Full article

(This article belongs to the Section Pest and Disease Management)

► Show Figures

Figure 1

21 pages, 2291 KiB

Open AccessArticle

How Well Can Reflectance Spectroscopy Allocate Samples to Soil Fertility Classes?

by Rong Zeng, David G. Rossiter, Jiapeng Zhang, Kai Cai, Weichang Gao, Wenjie Pan, Yuntao Zeng, Chaoying Jiang and Decheng Li

Agronomy 2022, 12(8), 1964; https://doi.org/10.3390/agronomy12081964 - 20 Aug 2022

Cited by 4 | Viewed by 1927

Abstract

Fertilization decisions depend on the measurement of a large set of soil fertility indicators, usually through laboratory determination, which is costly and time-consuming. Visible and near-infrared (vis-NIR) spectroscopy combined with machine learning can simultaneously predict various soil fertility indicators. Spectroscopy is inherently less [...] Read more.

Fertilization decisions depend on the measurement of a large set of soil fertility indicators, usually through laboratory determination, which is costly and time-consuming. Visible and near-infrared (vis-NIR) spectroscopy combined with machine learning can simultaneously predict various soil fertility indicators. Spectroscopy is inherently less accurate than direct laboratory determination. However, in many fertilization recommendation contexts, farmers mainly fertilize according to classified fertility indicators, rather than by continuous soil property values. These classes have defined limits of property values. We hypothesized that the additional inaccuracy from spectroscopy may not be important for properties grouped into classes. This study compared the indirect and direct prediction of soil fertility classes. Indirectly, by (1) using vis-NIR spectra with machine learning to predict 20 soil fertility indicators (pH, soil organic matter (SOM), cation exchange capacity (CEC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), alkali-hydrolyzable nitrogen (AN), available phosphorus (AP), available potassium (AK), calcium (Ca), magnesium (Mg), silicon (Si), sulfur (S), boron (B), iron (Fe), manganese (Mn), copper (Cu), Zinc (Zn), molybdenum (Mo) and chlorine (Cl)) and (2) allocating the indicators to soil fertility classes. Directly, by predicting soil fertility classes directly from vis-NIR spectra using machine learning. The prediction accuracy of these two methods were compared and the accuracies needed for the acceptable class allocation of the fertility indicators were determined. The example dataset is a soil spectral library from the Guizhou Province, southwest China. The model performance was evaluated by the overall allocation accuracy and tau index, which accounts for class imbalance. For direct allocation based on three fertility classes (low, medium and high), the overall allocation accuracy of eight properties (CEC, Cu, Si, Zn, S, Mn, Ca and Mg), nine properties (B, AN, TK, AK, SOM, TN, TP, Fe and Mo) and three properties (Cl, AP and pH) were within the range of 0.80–1.0, 0.60–0.80 and 0.40–0.60, respectively. For indirect allocation based on the same classes, the allocation accuracy of nine properties (TN, CEC, Cu, S, Zn, Si, Mn, Ca and Mg), nine properties (B, TK, pH, TP, AK, AN, Fe, Mo and SOM) and two properties (Cl and AP) were within the range of 0.80–1.0, 0.60–0.80 and 0.40–0.60, respectively. We conclude that vis-NIR spectroscopy was fairly successful for soil fertility class allocation for most of the soil properties, using either direct or indirect models. The advantage of indirect models is that both specific property values and soil fertility classes can be obtained at no increase in cost, while direct models are suggested when only soil fertility class information are available. Full article

(This article belongs to the Special Issue Soil Sustainability in the Anthropocene)

► Show Figures

Figure 1

15 pages, 2398 KiB

Open AccessArticle

Comparing Selection Criteria to Select Grapevine Clones by Water Use Efficiency

by Andreu Mairata, Ignacio Tortosa, Cyril Douthe, José Mariano Escalona, Alicia Pou and Hipólito Medrano

Agronomy 2022, 12(8), 1963; https://doi.org/10.3390/agronomy12081963 - 19 Aug 2022

Cited by 7 | Viewed by 1890

Abstract

The current climate change is forcing growth-adapted genotypes with a higher water use efficiency (WUE). However, the evaluation of WUE is being made by different direct and indirect parameters such as the instantaneous leaf WUE (WUE_i) and isotopic discrimination of carbon [...] Read more.

The current climate change is forcing growth-adapted genotypes with a higher water use efficiency (WUE). However, the evaluation of WUE is being made by different direct and indirect parameters such as the instantaneous leaf WUE (WUE_i) and isotopic discrimination of carbon (δ¹³C) content of fruits. In the present work, WUE has been evaluated in these two ways in a wide collection of grapevine genotypes, including Tempranillo and Garnacha clones, and Tempranillo on different rootstocks (T-rootstocks). A total of 70 genotypes have been analysed in four experimental fields over two years. The parameters used to measure WUE were the bunch biomass isotopic discrimination (δ¹³C) and the intrinsic WUE (WUE_i), defined as the ratio between net CO₂ assimilation and stomatal conductance. The genotypes with the highest and lowest WUE were identified, differences between them being found to be of more than 10%. Generally, the two parameters showed coincidences in the clones with the highest and lowest WUE, suggesting that both are valuable tools to classify genotypes by their WUE in grapevine breeding programs. However, δ¹³C seemed to be a better indicator for determining WUE because it represents the integration over the synthesis time of the sample analysed (mainly sugars from ripening grapes), which coincides with the driest period for the crop. Moreover, the WUE_i is a variable parameter in the plant and it is more dependent on the environmental conditions. The present work suggests that carbon isotopic discrimination could be an interesting parameter for the clonal selection criteria in grapevines by WUE. The main reasons were its better discrimination between clones, the fact that sampling is less time-consuming and easier to do than WUE_i, and that the samples can be stored for late determinations, increasing the number of samples that can be analysed. Full article

(This article belongs to the Special Issue Current Progress in Improving Water Use Efficiency of Vineyards)

► Show Figures

Figure 1

Figure 1
Linear regression between the natural logarithm intrinsic water use efficiency (WUEi, AN/gs) and stomatal conductance (gs) representing the clonal groupings analysed (LG: La Grajera; VN: Vitis Navarra; VP: Vitis Provedo; R: Roda). Full article ">Figure 2
Linear regression between carbon isotopic discrimination (13C) and WUEi of the data set grouped in the clone sets analysed (LG: La Grajera; VN: Vitis Navarra; VP: Vitis Provedo; R: Roda). ** p-value < 0.01; * p-value < 0.05; n.s: not significant. Full article ">Figure 3
Residual percentages relationship of intrinsic water use efficiency (WUEi) and carbon isotopic discrimination (13C) in the clonal groupings analysed (LG: La Grajera; VN: Vitis Navarra; VP: Vitis Provedo; R: Roda). Full article ">Figure 4
Relative position based on the residual percentage value of carbon isotopic discrimination (13C) and intrinsic water use efficiency (WUEi) in each group of clones and genotypes analysed (LG: La Grajera; VN: Vitis Navarra; VP: Vitis Provedo; R: Roda). Full article ">Figure 5
Linear regression between carbon isotopic discrimination (13C) and WUEi of the analysed groups separating efficient and very efficient genotypes (filled mark) and very inefficient genotypes (empty mark). Full article ">

31 pages, 2858 KiB

Open AccessEditor’s ChoiceReview

Irrigation Decision Support Systems (IDSS) for California’s Water–Nutrient–Energy Nexus

by Gaurav Jha, Floyid Nicolas, Radomir Schmidt, Kosana Suvočarev, Dawson Diaz, Isaya Kisekka, Kate Scow and Mallika A. Nocco

Agronomy 2022, 12(8), 1962; https://doi.org/10.3390/agronomy12081962 - 19 Aug 2022

Cited by 8 | Viewed by 6154

Abstract

California has unsustainable use of agricultural water and energy, as well as problems of severe drought, nitrate pollution and groundwater salinity. As the leading producer and exporter of agricultural produce in the United States, 5.6 percent of California’s energy is currently used for [...] Read more.

California has unsustainable use of agricultural water and energy, as well as problems of severe drought, nitrate pollution and groundwater salinity. As the leading producer and exporter of agricultural produce in the United States, 5.6 percent of California’s energy is currently used for pumping groundwater. These problems and new regulatory policies (e.g., Sustainable Groundwater Management Act, Irrigated Lands Regulatory Program) pressure growers to schedule, account and maintain records of water, energy and nutrients needed for crop and soil management. Growers require varying levels of decision support to integrate different irrigation strategies into farm operations. Decision support can come from the public or private sector, where there are many tradeoffs between cost, underlying science, user friendliness and overall challenges in farm integration. Thus, effective irrigation management requires clear definitions, decision support and guidelines for how to incorporate and evaluate the water–nutrient–energy nexus benefits of different practices and combinations of practices under shifting water governance. The California Energy Commission-sponsored Energy Product Evaluation Hub (Cal-EPE Hub) project has a mission of providing science-based evaluation of energy-saving technologies as a direct result of improved water management for irrigation in agriculture, including current and future irrigation decision support systems in California. This project incorporates end-user perceptions into evaluations of existing decision support tools in partnership with government, agricultural and private stakeholders. In this article, we review the policy context and science underlying the available irrigation decision support systems (IDSS), discuss the benefits/tradeoffs and report on their efficacy and ease of use for the most prevalent cropping systems in California. Finally, we identify research and knowledge-to-action gaps for incorporating irrigation decision support systems into new incentives and requirements for reporting water and energy consumption as well as salinity and nitrogen management in the state of California. Full article

(This article belongs to the Special Issue Agricultural Water Conservation: Tools, Strategies, and Practices - Series II)

► Show Figures

Figure 1

Figure 1
Distribution of irrigation methods, major crops and irrigation water salinity levels in hydrologic regions of California. Full article ">Figure 2
Conceptual illustration of integration and application of imagery (IDSS 1 is satellite imagery, 2 is aerial reflectance, and 3 is drone imagery using multispectral/thermal cameras), canopy (IDSS 4 and 5 based on crop evapotranspiration and other canopy-based parameters) and soil-based IDSS (IDSS 6 and 7 based on volumetric water content and 8 based on soil water potential) in a processing tomato field. Eddy covariance tower and neutron moisture probes are useful to estimate a complete water balance for validation of these available IDSS measurements. Artwork by Dr. Bonnie McGill. Full article ">Figure 3
Remote-sensing imagery-based IDSS provided by Ceres Imaging Inc. (Oakland, CA, USA) for evaluating distribution uniformity using colorized NDVI and thermal maps. (a) Warmest areas of the field were under water stress and showed lowest vigor at early crop growth stage because of low dripline pressure due to topographical differences; (b) Increased pressure of driplines after identifying the stress led to more uniform distribution of water application with homogenous crop vigor saving an estimated yield worth USD 20,000. Full article ">Figure 4
Innovation–adoption–validation cycle of irrigation decision support system. Artwork by Dr. Bonnie McGill. Full article ">

12 pages, 15498 KiB

Open AccessArticle

Potential Roles of Three ABCB Genes in Quinclorac Resistance Identified in Echinochloa crus-galli var. zelayensis

by Yuanlin Qi, Yongli Guo, Xudong Liu, Yuan Gao, Yu Sun, Liyao Dong and Jun Li

Agronomy 2022, 12(8), 1961; https://doi.org/10.3390/agronomy12081961 - 19 Aug 2022

Cited by 1 | Viewed by 1662

Abstract

Echinochloa crus-galli var. zelayensis is a variant of E. crus-galli (L) Beauv, and it is the most pernicious weed in the east of China. Quinclorac, as synthetic auxin herbicide, could control this kind of weed effectively. In this study, two populations were [...] Read more.

Echinochloa crus-galli var. zelayensis is a variant of E. crus-galli (L) Beauv, and it is the most pernicious weed in the east of China. Quinclorac, as synthetic auxin herbicide, could control this kind of weed effectively. In this study, two populations were used to further research the mechanism of quinclorac resistance, and the EcABCB1, EcABCB4 and EcABCB19 was functionally characterized to determine their roles in quinclorac resistance. It was found that root growth of quinclorac-resistant biotype SSXB-R was less inhibited by quinclorac at 5 μM and 50 μM when compared with the susceptible biotype JNNX-S. The results show that the IAA variations in root tip of JNNX-S were significantly higher than SSXB-R at 12 h after treatment with quinclorac (50 μM) and 1-N-naphthylthalamic acid (100 μM). There are no significant differences in IAA variations of the basal part of the root between susceptible and resistant biotypes after treatment with quinclorac and 1-N-naphthylthalamic acid (NPA). The transcript level of EcABCB1 and EcABCB19 in the root of JNNX-S showed down-regulated and up-regulated after treatment with quinclorac (TWQ) at 6 h in susceptible and resistant biotypes compared with control, respectively. The transcript level for EcABCB4 in the root showed up-regulated after TWQ at 12 h only in susceptible biotypes compared with control. It was found that the IC₅₀ to quinclorac of AtABCB4 and AtABCB19 mutants were significantly higher than the parent line Col-0. Full article

(This article belongs to the Special Issue Herbicides Toxicology and Weeds Herbicide-Resistant Mechanism)

► Show Figures

Figure 1

Figure 1
Root length of two biotypes at 7 days after treatment with 0 μM, 0.5 μM, 5 μM and 50 μM quinclorac. S represents the susceptible biotypes (JNNX-S), and R represents the resistant biotypes (SSXB-R). Data are the mean values of at least 10 biological replicates. The standard errors of the means are described by vertical bars. ANOVA significance groupings are shown as a, b and c. Full article ">Figure 2
Root length of two biotypes at 7 days after treatment with 0 μM, 1 μM, 10 μM and 100 μM 1-N-naphthylthalamic acid (NPA). S represents the susceptible biotypes (JNNX-S), and R represents the resistant biotypes (SSXB-R). Data are the mean values of at least 10 biological replicates. The standard errors of the means are described by vertical bars. ANOVA significance groupings are shown as a and b. Full article ">Figure 3
IAA contents in root tips were measured in S (JNNX-S) and R biotypes (SSXB- R) after treatment with quinclorac (50 μM) at 0 h, 6 h, 12 h and 24 h. Data are the mean values of at least three biological replicates. The standard errors of the means are described by vertical bars. Full article ">Figure 4
IAA contents in root tips were measured in S (susceptible, JNNX-S) and R biotypes (resistant, SSXB-R) after treatment with 1-N-naphthylthalamic acid (NPA) (100 μM) at 0 h, 6 h, 12 h and 24 h. Data are the mean values of at least three biological replicates. The standard errors of the means are described by vertical bars. Full article ">Figure 5
IAA contents in upper root tissues were measured in S (susceptible, JNNX-S) and R biotypes (resistant, SSXB-R) after treatment with quinclorac (50 μM) at 0 h, 6 h, 12 h and 24 h. Data are the mean values of at least three biological replicates. The standard errors of the means are described by vertical bars. Full article ">Figure 6
IAA contents in upper root tissues were measured in S (susceptible, JNNX-S) and R biotypes (resistant, SSXB-R) after treatment with 1-N-naphthylthalamic acid (NPA) (100 μM) at 0 h, 6 h, 12 h and 24 h. Data are the mean values of at least three biological replicates. The standard errors of the means are described by vertical bars. Full article ">Figure 7
Relative transcript level in roots of 3 candidate genes after treatment with quinclorac in S (susceptible, JNNX-S) and R (resistant, SSXB-R) biotypes. (A–C) represent the EcABCB1, EcABCB4 and EcABCB19. Full article ">Figure 8
Root length of 3 biotypes at 7 days after treatment with 0 μM, 1.3 μM, 3.7 μM, 11.1 μM, 33.3 μM, 100 μM and 300 μM quinclorac. (A–C) represent the comparison of root length between AtABCB1, AtABCB4, AtABCB19 and the parent line. Data are the mean values of at least 10 biological replicates. The standard errors of the means are described by vertical bars. Full article ">

14 pages, 3406 KiB

Open AccessArticle

Characteristics on the Spatial Distribution of Droplet Size and Velocity with Difference Adjuvant in Nozzle Spraying

by Xinpeng Li, Liping Chen, Qin Tang, Longlong Li, Wu Cheng, Peng Hu and Ruirui Zhang

Agronomy 2022, 12(8), 1960; https://doi.org/10.3390/agronomy12081960 - 19 Aug 2022

Cited by 5 | Viewed by 2191

Abstract

The spatial distribution of droplet size and velocity affects the deposition and distribution on the target. In order to investigate the influence of different adjuvant and pressures on the spatial distribution of droplet size and velocity in atomization area of different nozzles, air [...] Read more.

The spatial distribution of droplet size and velocity affects the deposition and distribution on the target. In order to investigate the influence of different adjuvant and pressures on the spatial distribution of droplet size and velocity in atomization area of different nozzles, air induction flat fan nozzle IDK120-03, multi-range flat fan nozzle LU120-03 and anti-drift flat fan nozzle AD120-03 were selected. Phase Doppler Interferometer (PDI) was used to analyze and compare the distribution of droplet size and velocity in the atomization area of three nozzles when four typical adjuvant Maisi, Maidao, Adsee AB-600 and Surun sprayed at different pressures. The results show that the volume median diameter of droplet size has no obvious change along the vertical direction of the nozzle center and increases with distance in the horizontal direction, the droplet size decreases with increasing pressure at the same position, the adjuvant all increases the droplet size (about 12%, 12%, 10% and 9% for Maisi, Maidao, Surun and Adsee AB-600, respectively), IDK120-03 nozzle droplet size is the largest and LU120-03 nozzle is the smallest in the same position. For droplet velocity distribution, droplet velocity decrease in distance along the vertical and horizontal direction, respectively, the droplet velocity increases with increasing pressure at the same position, compared with water, the droplet velocity increased by about 13%, 9%, 8%, and 4% for Maisi, Maidao, Surun, and Adsee AB-600, respectively, the velocity of AD nozzle is the largest and IDK nozzle is the smallest at the same position. The experiment can provide a basis for the selection of adjuvants and nozzles in pesticide application, and provide a data base for studying the distribution of droplets on the target. Full article

(This article belongs to the Special Issue Development of Crop Protection Mechanical Engineering Technology, Evaluation of Efficacy and Safety of Pesticide Spraying)

► Show Figures

Figure 1

20 pages, 2790 KiB

Open AccessArticle

An Integration of Transcriptomic Data and Modular Gene Co-Expression Network Analysis Uncovers Drought Stress-Related Hub Genes in Transgenic Rice Overexpressing OsAbp57

by Muhammad-Redha Abdullah-Zawawi, Lay-Wen Tan, Zuraida Ab Rahman, Ismanizan Ismail and Zamri Zainal

Agronomy 2022, 12(8), 1959; https://doi.org/10.3390/agronomy12081959 - 19 Aug 2022

Cited by 3 | Viewed by 2238

Abstract

Auxin receptor plays a significant role in the plant auxin signalling pathway in response to abiotic stress. Recently, we found that transgenic rice overexpressing ABP57 had higher drought tolerance than the wild-type cultivar, MR219, due to the fact of its enhanced leaf photosynthetic [...] Read more.

Auxin receptor plays a significant role in the plant auxin signalling pathway in response to abiotic stress. Recently, we found that transgenic rice overexpressing ABP57 had higher drought tolerance than the wild-type cultivar, MR219, due to the fact of its enhanced leaf photosynthetic rate and yields under drought stress. We performed a microarray study on this line to investigate the underlying mechanisms contributing to the observed phenotype. After microarray data filtering, 3596 genes were subjected to modular gene co-expression network (mGCN) development using CEMiTool, an R package. We identified highly related genes in 12 modules that could act to specific responses towards drought or any of the abiotic stress types. Gene set enrichment and overrepresentation analyses for modules extracted two highly upregulated modules that are involved in drought-related biological processes such as transmembrane transport of metal ions and response to oxidative stress. Finally, 123 hub genes were identified in all modules after integrating co-expression information with physical interaction data. In addition, the interplay of significant pathways between the metabolism of chlorophyll and flavonoid and the signalling pathways of MAPK, IAA, and SA inferred the concurrent involvement of stress tolerance response. Collectively, our findings seek new future directions for breeding strategies in rice tolerant improvements. Full article

(This article belongs to the Special Issue Omics Approaches for Crop Improvement)

► Show Figures

Figure 1

Figure 1
qPCR validations on six randomly selected DEGs. The bar plot represents the mean ± standard error for two biological replicates and three technical replicates. The difference in gene expression between the control (WT) and Abp57-OE was determined by a one-way ANOVA method with a cut-off p-value < 0.05. The error bars indicate the standard error. Full article ">Figure 2
CEMiTool outputs for the OsAbp57-OE line microarray dataset. (A) Clustering dendrogram of genes based on the expression profiles. The turquoise colour indicates MR219, and the red colour represents the OsAbp57-OE line. (B) Scale-free topology (R2) and mean connectivity to identify the soft-threshold power (β) between 1 and 20. The scale-freeness of the network was determined at a soft threshold of 14, above the R2 threshold of 0.8. (C) Gene set enrichment analysis for module activity of the OsAbp57-OE line (OE) and MR219 (WT). The size and colour of the modules represent the normalised enrichment score (NES). All modules were upregulated in OE except M6, with downregulation in OE and upregulation in WT. Full article ">Figure 3
Bar graph for the top ten GO terms enriched between genes in modules (A) M2 and (C) M3, respectively, and gene sets from the Phytozome database. The dashed line represents the -log10 adjusted p-value of 0.01. Interaction network of modules (B) M2 and (D) M3. The top ten hubs’ colours are shown based on the originality of hubs present in the CEMiTool co-expression module (blue) or rice PPI dataset (red) on the STRING database. Full article ">Figure 4
Interaction network for all hub genes in OsAbp57-OE: (A) modules M1–M12; (B) stress-related hub genes: (i) MDH, (ii) HSP70, and (iii) HRZ2. Full article ">Figure 5
Pathway mapping analysis of OsAbp57-OE. (A) Classification of hub genes in the modular network into five main pathway maps: cellular processes, environmental information processing, genetic information processing, and organismal systems; (B) interaction between M7 hubs in the porphyrin and chlorophyll metabolism pathway, and phenylpropanoid biosynthesis maps are represented with red lines. Full article ">Figure 6
Interaction between hub genes in MAPK signalling pathway and plant hormone signal transduction maps. Interaction is represented in red lines. Full article ">

13 pages, 3486 KiB

Open AccessEditor’s ChoiceArticle

Tender Leaf Identification for Early-Spring Green Tea Based on Semi-Supervised Learning and Image Processing

by Jie Yang and Yong Chen

Agronomy 2022, 12(8), 1958; https://doi.org/10.3390/agronomy12081958 - 19 Aug 2022

Cited by 11 | Viewed by 2805

Abstract

Tea is one of the most common beverages in the world. Automated machinery that is suitable for plucking high-quality green tea is necessary for tea plantations and the identification of tender leaves is one of the key techniques. In this paper, we proposed [...] Read more.

Tea is one of the most common beverages in the world. Automated machinery that is suitable for plucking high-quality green tea is necessary for tea plantations and the identification of tender leaves is one of the key techniques. In this paper, we proposed a method that combines semi-supervised learning and image processing to identify tender leaves. Both in two-dimensional and three-dimensional space, the three R, G, and B components of tender leaves and their backgrounds were trained and tested. The gradient-descent method and the Adam algorithm were used to optimize the objective function, respectively. The results show that the average accuracy of tender leaf identification is 92.62% and the average misjudgment rate is 18.86%. Our experiments have shown that green tea tender leaves in early spring can be identified effectively using the model based on semi-supervised learning, which has strong versatility and perfect adaptability, so as to improve the problem of deep learning requiring a large number of labeled samples. Full article

(This article belongs to the Special Issue Advanced Technologies in Precision Processing and Modeling in Agriculture)

► Show Figures

Figure 1

24 pages, 8099 KiB

Open AccessArticle

In Vitro Regeneration of Stevia (Stevia rebaudiana Bertoni) and Evaluation of the Impacts of Growth Media Nutrients on the Biosynthesis of Steviol Glycosides (SGs)

by Asish Kumar Ghose, Siti Nor Akmar Abdullah, Muhammad Asyraf Md Hatta and Puteri Edaroyati Megat Wahab

Agronomy 2022, 12(8), 1957; https://doi.org/10.3390/agronomy12081957 - 19 Aug 2022

Cited by 7 | Viewed by 3768

Abstract

A plant tissue culture protocol from stevia was optimized for the production of planting materials and the natural sweetener, rebaudioside A. The highest survivability (88.90% ± 5.55) of explants was achieved at 15 and 30 days after culture initiation (DACI) on Murashige and [...] Read more.

A plant tissue culture protocol from stevia was optimized for the production of planting materials and the natural sweetener, rebaudioside A. The highest survivability (88.90% ± 5.55) of explants was achieved at 15 and 30 days after culture initiation (DACI) on Murashige and Skoog (MS) media by sterilization with 30% Clorox (5 min) and 10% Clorox (10 min), respectively. Supplementation of MS with 0.50 mg/L 2,4-Dichlorophenoxyacetic acid (2,4-D) and 0.10 mg/L zeatin produced 50% callus at 15 DACI while 1.50 mg/L 2,4-D and 0.10 mg/L zeatin at 30 DACI increased callus production to 76.67%. The highest shoot proliferation per callus was achieved with 10.00 mg/L 6-benzyl amino purine (BAP) in MS at 15 DACI (5.80) and 30 DACI (12.33). The longest shoots of 4.31 cm and 6.04 cm at 15 and 30 DACI, respectively, were produced using BAP (10.00 mg/L) and 1.00 mg/L naphthalene acetic acid (NAA). MS media (0.50 strength) induced 2.86 and 6.20 roots per shoot and produced 3.25 cm and 7.82 cm long roots at 15 and 30 DACI, respectively. Stevia grown on 0.25 MS accumulated the highest concentration of rebaudioside A (6.53%), which correlated with the expression level of its biosynthetic gene uridine-diphosphate-dependent (UDP)-glycosyltransferase (UGT76G1). Full article

(This article belongs to the Special Issue Medicinal Plants—Natural Sources of Bioactive Secondary Metabolites)

► Show Figures

Figure 1

Figure 1
Effect of surface sterilization on explants of stevia by different concentrations of Clorox (0, 5, 10, 15, 20, and 30%) for different periods of time (5, 10, 15, and 20 min): (a) explant with fungal contamination; (b) explant with bacterial contamination; (c) non-contaminated explant; and (d) survived explant. Full article ">Figure 2
Induced calli from the explants of stevia at 30 DACI; (a) induced callus on MS media with 0.10 mg/L 2, 4-D and 0.10 mg/L zeatin; (b) induced callus on MS media with 0.50 mg/L 2, 4-D and 0.10 mg/L zeatin; (c) induced callus on MS media with 1.00 mg/L 2, 4-D and 0.10 mg/L zeatin; and (d) induced callus on MS media with 1.50 mg/L 2, 4-D and 0.10 mg/L zeatin. Full article ">Figure 3
Frequencies of callus induction during in vitro culture of stevia on MS media supplemented with different concentrations of 2,4-D and zeatin: (a) compact callus; (b) friable callus; (c) total callus; and (d) non-response of stevia explants. Bars denote the mean of three replications per treatment ± SE (standard error). Mean values with the same letters are not significantly different based on the Student’s t-test at p = 0.05. Full article ">Figure 4
Regenerated shoots of stevia from induced calli on MS media supplemented with different concentrations of BAP and NAA at 30 DACI: (a) regenerated shoots on MS media with 1.00 mg/L BAP and 1.00 mg/L NAA; (b) regenerated shoots on MS media with 5.00 mg/L BAP and 0.00 mg/L NAA; and (c) regenerated shoots on MS media with 10.00 mg/L BAP. Full article ">Figure 5
Shoot proliferation of stevia on MS media supplemented with different concentrations of BAP and NAA at 15 and 30 days after inoculation (DACI): (a) No. of shoots induced per callus; (b) Length of induced shoots; (c) No. of leaves per shoot; and (d) Percentage of shoot proliferation. Bars denote the mean of three replications per treatment ± SE (standard error). Mean values with the same letters are not significantly different based on the Student’s t-test at p = 0.05. Full article ">Figure 6
Regenerated roots from stevia shoot on different strengths of MS media at 30 DACI: (a) initiated roots on 0.25 MS media; (b) initiated roots on 0.50 MS media; and (c) initiated roots on 1.00 MS media. Full article ">Figure 7
Root initiation of stevia from shoot grown on different strengths of MS media at 15 and 30 days after inoculation (DACI): (a) No. of roots initiated per shoot; (b) length of induced roots; and (c) percentage of root production. Bars denote the mean of three replications per treatment ± SE (Standard Error). Mean values with the same letters are not significantly different based on the Student’s t-test at p = 0.05. Full article ">Figure 8
Stevioside and rebaudioside A content in the leaves of stevia rooted on different strengths (0.00, 0.25, 0.50, 0.75, and 1.00) of MS media. Bars denote the mean of three replications per treatment ± SE (standard error). Mean values with the same letters are not significantly different based on the Student’s t-test at p = 0.05. Full article ">Figure 9
Purified total RNAs isolated from stevia rooted on different strengths of MS (0.00, 0.25, 0.50, 0.75, and 1.00) media. The total RNAs analyzed by electrophoresis on 1.2% (w/v) agarose gel. Full article ">Figure 10
Expression levels of UGT76G1, UGT74G1, and UGT85C2 in stevia grown on 0.00, 0.25, 0.50, 0.75 and 1.00 strengths of MS media. The expression was normalized with three reference genes Actin (AF548026.1), Aquaporin (DQ269455.1), and Calmodulin (AF474074.1). Bars denote the mean of three biological replications per treatment ± SE (standard error). Mean values with the same letters are not significantly different based on the Student’s t-test at p = 0.05. Full article ">

16 pages, 4602 KiB

Open AccessArticle

Evaluation of Bacillus velezensis Biocontrol Potential against Fusarium Fungi on Winter Wheat

by Anzhela Mikhailovna Asaturova, Natalya Andreevna Zhevnova, Natalia Sergeevna Tomashevich, Tatiana Mikhailovna Sidorova, Anna Igorevna Homyak, Valentina Mikhailovna Dubyaga, Vladimir Dmitrievich Nadykta, Artem Pavlovich Zharikov, Yuri Irodionovich Kostyukevich and Boris Sergeevich Tupertsev

Agronomy 2022, 12(8), 1956; https://doi.org/10.3390/agronomy12081956 - 19 Aug 2022

Cited by 5 | Viewed by 2720

Abstract

Fungi of the genus Fusarium are economically significant pathogens in most wheat-growing regions worldwide. The biocontrol agents Bacillus velezensis BZR 336 g and BZR 517 were tested for growth inhibition of F. graminearum BZR 4. The results demonstrated that the strains are capable [...] Read more.

Fungi of the genus Fusarium are economically significant pathogens in most wheat-growing regions worldwide. The biocontrol agents Bacillus velezensis BZR 336 g and BZR 517 were tested for growth inhibition of F. graminearum BZR 4. The results demonstrated that the strains are capable of deforming and destroying hyphae. The modified bioautography technique showed that the strains produce iturin A and surfactin, which probably explains the mechanism of pathogen inhibition. Furthermore, lipopeptides were detected and identified in two samples by the HPLC-HRMS. Compounds such as surfactin and their isomers and homologues were found in both samples. An experiment on an artificial infectious background in a climatic chamber established that the biological effectiveness of strains is close to that of chemical and biological references. Cultivation of plants with B. velezensis showed that the strains are likely to reduce the stress load. An efficacy of up to 45.0% was determined for bioagents BZR 336 g and BZR 517 in field trials, while the yield was up to 7.9 t/ha. The use of B. velezensis BZR 336 g and BZR 517 as biocontrol agents provides an environmentally friendly approach to the control of Fusarium rots on wheat, reduction of the pesticide load, and hence quality harvest. Full article

(This article belongs to the Special Issue Metabolomic and Transcriptomic Response of Plants to Beneficial Microbes)

► Show Figures

Figure 1

14 pages, 3376 KiB

Open AccessArticle

An R2R3-Type Transcription Factor OsMYBAS1 Regulates Seed Germination under Artificial Accelerated Aging in Transgenic Rice (Oryza sativa L.)

by Rong Wu, Yunqian Ding, Chenyong Li, Bangkui Wu, Zhongji Huang, Zhenan Li, Xiaomin Wang and Guangwu Zhao

Agronomy 2022, 12(8), 1955; https://doi.org/10.3390/agronomy12081955 - 19 Aug 2022

Cited by 2 | Viewed by 1817

Abstract

MYB-type transcription factors play an essential regulatory role in seed germination and the response to seedling establishment stress. This study isolated a rice R2R3-MYB transcription factor, OsMYBAS1, and functionally characterized its role in seed germination. There was no significant difference in the germination [...] Read more.

MYB-type transcription factors play an essential regulatory role in seed germination and the response to seedling establishment stress. This study isolated a rice R2R3-MYB transcription factor, OsMYBAS1, and functionally characterized its role in seed germination. There was no significant difference in the germination rate of each transgenic line in the standard germination test. However, compared to the germination rate of the wild type (WT) measured in the artificial accelerated aging test, the germination rates of the overexpression lines OE-OsMYBAS1-1 and OE-OsMYBAS1-2 were significantly increased by 25.0% and 21.7%, respectively. In contrast, the germination rates of the knockout mutants osmybas1-1 and osmybas1-2 were decreased by 21.7% and 33.3%, respectively. Additionally, the above data indicated that OsMYBAS1 possibly plays a positive role in rice seed germination. Moreover, the antioxidant enzyme activities of OsMYBAS1-overexpressing plants were enhanced by 38.5% to 151.0% while the superoxide dismutase (SOD) enzyme activity of osmybas1 mutants was decreased by 27.5%, and the malondialdehyde (MDA) content was increased by 24.7% on average. Interestingly, the expression of the antioxidation-related genes OsALDH3, OsAPX3, and OsCATC was enhanced in the OsMYBAS1 overexpression lines, which is consistent with the above results. Furthermore, transcriptome sequencing determined 284 differentially expressed genes (DEGs), which were mainly involved in the carbohydrate metabolic process, glycerolipid metabolism, and glycerophospholipid metabolism. Therefore, these findings provide valuable insight into the breeding of new rice varieties with high seed germination. Full article

(This article belongs to the Section Crop Breeding and Genetics)

► Show Figures

Figure 1

17 pages, 6768 KiB

Open AccessArticle

Investigation of Solanum carolinense Dominance and Phytotoxic Effect in Festuca arundinacea with Special Reference to Allelochemical Identification, Analysis of Phytohormones and Antioxidant Mechanisms

by Lee-Rang Kim, Arjun Adhikari, Yosep Kang, Ho-Jun Gam, Sang-Mo Kang, Ki-Yong Kim and In-Jung Lee

Agronomy 2022, 12(8), 1954; https://doi.org/10.3390/agronomy12081954 - 19 Aug 2022

Cited by 8 | Viewed by 2015

Abstract

Exposure to invasive weeds in pasturelands may result in significant losses and toxicity in forage crops. These species may also contain a compound that may be toxic as well as beneficial depending upon the effect induced. The Ministry of Environment of the Republic [...] Read more.

Exposure to invasive weeds in pasturelands may result in significant losses and toxicity in forage crops. These species may also contain a compound that may be toxic as well as beneficial depending upon the effect induced. The Ministry of Environment of the Republic of Korea has now recognized Solanum carolinense (Horsenettle)—an invasive weed species—as a potential threat to forage crops in pasturelands and to the entire agro-ecosystem. As a forage crop, Festuca arundinacea (Tall fescue) is one of the major economical crops and diets of livestock; in this study, the competition patterns of Solanum carolinense and Festuca arundinacea were examined with respect to their seeding ratios and growth periods. In addition, an extract from the root of Solanum carolinense (SCE) was prepared and treated at 2500 ppm and 5000 ppm in a Festuca arundinacea plant to observe its effect. The experimental results showed that as the growth period of the Horsenettle and the SCE treatment increased, the germination rate, plant height, root length, fresh weight, and dry weight of the tall fescue were significantly decreased. Moreover, the SCE treatment significantly increased the quantities of reactive oxygen species (O₂⁻ and H₂O₂), antioxidants (Catalase and Peroxidase), and endogenous phytohormones (Abscisic acid and Salicylic acid), and simultaneously decreased the superoxide dismutase content in the tall fescue shoots. Furthermore, we identified several glycoalkaloids from the SCE extract, among which Solanidan-3-ol, (3β,5α)’ possessed a higher number (52%). Based on these results, we predicted that the Solanidan-3-ol, (3β,5α)’ present in horsenettle has a major role in imposing phytotoxicity on agricultural crops. The glycoalkaloids in the Solanum species have been reported to possess both phytotoxic and therapeutic uses. Based on this concept, we believe that the compound available in Solanum carolinense could be used in developing crop protection or medicinal products through broader research. Conversely, our findings also showed the probable risk of horsenettle to the agro-ecosystem, especially in terms of forage production. Full article

► Show Figures

Figure 1

12 pages, 321 KiB

Open AccessArticle

Nitrogen Use Efficiency and Partitioning of Dairy Heifers Grazing Perennial Ryegrass (Lolium perenne L.) or Pasture Brome (Bromus valdivianus Phil.) Swards during Spring

by Ignacio E. Beltran, Daniel Tellez, Jaime Cabanilla, Oscar Balocchi, Rodrigo Arias and Juan Pablo Keim

Agronomy 2022, 12(8), 1953; https://doi.org/10.3390/agronomy12081953 - 18 Aug 2022

Viewed by 1947

Abstract

The aim of the study was to evaluate the effect of grazing Lolium perenne (Lp) and Bromus valdivianus (Bv) on the average daily weight gain (ADG) and nitrogen use efficiency (NUE) of Holstein Friesian heifers. Thirty heifers strip-grazed two pasture treatments (Lp and [...] Read more.

The aim of the study was to evaluate the effect of grazing Lolium perenne (Lp) and Bromus valdivianus (Bv) on the average daily weight gain (ADG) and nitrogen use efficiency (NUE) of Holstein Friesian heifers. Thirty heifers strip-grazed two pasture treatments (Lp and Bv) under a randomized complete block design (n = 3). Nutrient concentration and pasture intake were determined. Urine samples were taken, and the total volume of urine and microbial growth were estimated. Retained nitrogen (N), N intake, N excreted in feces and urine and the nitrogen use efficiency (NUE) were calculated. Lolium perenne showed greater WSC and ME but lower NDF than Bv, whereas crude and soluble protein were unaffected. There were no effects of species on ADG or feed conversion, and DMI was not affected by grass species, or the synthesis of microbial protein and purine derivatives. Ammonia in the rumen, urinary N and total N excreted were greater for heifers grazing Bv. In conclusion, the consumption of forage species did not alter the ADG or NUE of grazing heifers, but N partitioning was modified for heifers grazing Bv, due to the lower WSC/CP ratio compared with Lp. Full article

(This article belongs to the Special Issue Assessing Sustainability of Ruminant Livestock Forage-Based Systems)

Journal Menu

Journal Browser

Agronomy, Volume 12, Issue 8 (August 2022) – 253 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI