CN109496765B - Method for breeding Chinese herbaceous peony through rootstocks - Google Patents

Abstract

The invention relates to a method for propagating Chinese herbaceous peony by rhizome, which comprises the following steps: 1) cutting the root and stem of Paeonia lactiflora into multiple segments; 2) and carrying out field planting on the cut sections. The cutting propagation method for the peony roots provided by the invention is simple in flow and easy to operate, breaks through the characteristics of low germination rate, variety specificity and the like of the traditional propagation method, and the obtained root and stem segments are high in germination rate and seedling rate and high in propagation efficiency, is the first attempt and practice in the peony propagation field, provides a new thought for large-scale production of peony seedlings, and has important production and application values.

Description

Method for breeding Chinese herbaceous peony through rootstocks

Technical Field

The invention relates to the technical field of peony seedling propagation, and particularly relates to a peony rhizome cutting propagation method and application thereof.

Background

Paeonia lactiflora (Paeonia lactiflora) is an important ornamental plant in the world, and the reputation of 'flower phase' is always in constant load, is still honored as 'May flower spirit' and is always favored by people from ancient times to present. In the international fresh cut flower market, the peony cut flower is bright and has a wide prospect. However, the production of peony seedlings is relatively delayed at present, and a new technical breakthrough is urgently needed to meet the increasingly expanding market demand.

A great deal of attempts and researches are carried out around the propagation of peony seedlings, and the researches mainly comprise sowing, plant division, cuttage (stem cutting and root cutting), layering, tissue culture and the like. Because the seedlings generated by seed sowing are mostly subjected to genetic character separation, the excellent characteristics of the original parents cannot be maintained, and in addition, a large number of excellent cut flower peony varieties are mostly in double-petal or highly-double-petal flower types, the seed setting rate is low, and even the seed setting is difficult. Therefore, the sowing method is only applied to the breeding of new varieties. The plant division can ensure the excellent characteristics of the germplasm resources to the maximum extent, and the management is convenient, the operation is easy, so the method is widely applied. However, a 3-year-old mother plant is propagated by a plant division method, and only about 3-4 daughter plants can be obtained, so that the propagation coefficient of the plant division method is low, and the demand of a large-scale fresh-cut flower market in the future cannot be met. Although a great deal of exploration work is carried out on the cuttage and layering of the Chinese herbaceous peony for seedling breeding, a large technical bottleneck still exists at present, the technical process is complex, the management difficulty is high, and the breeding results among varieties have large difference, so that the large-scale application is not realized in practice. In recent years, the tissue culture technology of the peony has made great progress, but a long way is needed to form a complete technical system, and some key technologies, such as easy browning of explants, callus redifferentiation, difficulty in domestication and transplantation of tissue culture seedlings and the like, still need to be overcome.

Therefore, the conventional breeding technical method of the Chinese herbaceous peony is difficult to improve the breeding efficiency of the Chinese herbaceous peony in a short time so as to meet the expanding market demand. Therefore, it is necessary to invent a new high-efficiency and reliable peony seedling breeding method.

Disclosure of Invention

The invention relates to a method for rapid and efficient propagation of Chinese herbaceous peony through rhizomes, which comprises the following steps:

1) cutting the root and stem of Paeonia lactiflora into multiple segments;

2) carrying out field planting on the cut sections;

the rhizome is obtained by intercepting the following steps: digging out the underground part of the peony completely, judging the growth direction of the rhizome according to the growth direction of the stems of the overground part, dividing the underground part along the growth direction of the rhizome, keeping the rhizome intact in the dividing process, and removing fleshy roots attached to the rhizome to obtain the peony root-bark cutting machine.

The rootstock grows downwards along the stem, and the growth direction of the rootstock is the growth direction of the rootstock when the rootstock is extended downwards along the direction of the overground stem.

The underground part of the peony has a complex structure, the traditional research always considers that the deep underground part of the plant is only a fleshy root, the invention has relatively clear understanding on the structure of the underground part for the first time, the fleshy root is wrapped with a rootstock growing directionally, and the rootstock has very strong meristematic capacity, and the peony plant can be efficiently and quickly propagated by independently planting the rootstock in a field.

Preferably, the length of the cutting segment is 2-5 cm. The rhizome is cut into 2-5 cm long sections, so that more than one hidden bud can be ensured to be arranged on each rhizome section, and non-germination or difficult germination can be prevented.

Preferably, the specific cutting method of the cut segments is to cut the first segment at a position 2-5 cm below the bud base of the rootstock bud at the top of the rootstock by taking the bud base as a starting point, and then continue cutting until all the rootstocks are cut into segments. The rootstock bud is used as a cutting starting point, and the rootstock developed in the current year can be utilized to the maximum extent.

Preferably, the rhizome is cut in a direction perpendicular to the longitudinal axis of the rhizome, which advantageously minimizes wound area and prevents decay due to infection. During specific operation, the cutting length can be reasonably adjusted according to the specific development condition of the rhizome, the diameter of the upper rhizome is thin, the cutting section can be properly long, and the lower rhizome is thick.

Preferably, during the cutting process, the knife is a stainless steel art knife or pruning shears. Fresh rootstocks are directly cut by a stainless steel art knife, the blade is thin, the rigidity is high, the toughness is strong, the cut edge is sharp, and the cut edge is flat and smooth and is beneficial to wound healing; the aged or dehydrated rhizome is cut by pruning shears, so that force is conveniently exerted, and the rhizome tissue is prevented from being difficult to cut due to the increase of toughness.

Preferably, the rhizomes are taken from plants more than 2 years after the division propagation. By taking the plants of the above ages, more well developed rhizome cuts can be obtained. For the Chinese herbaceous peony with other propagation modes, firstly, the Chinese herbaceous peony is difficult to bud, and secondly, the growth period of rootstocks formed after the germination is longer. For example, for seedlings propagated by seeds, the method can be adopted after the seedlings grow into adults, and the propagation takes about 3-4 years to obtain robust rootstocks. For the plant division seedling, large amount of rootstocks can be easily obtained, and the plant more than 2 years after the plant propagation has strong vitality and is suitable for the development of the meristem.

Preferably, the rhizomes are cut at 9-10 months. At the moment, the annual rhizome is already formed, the accumulation of the photoproduct in the rhizome is sufficient, and the temperature is high, thus being beneficial to promoting the healing of the wound and the development of a new root.

Preferably, when the fleshy root is obtained, cutting off the stem of the peony plant at a position which is about 8-12 cm away from the ground surface, and taking out the rest part of the root. Before the seedlings are lifted, the stalks are cut off to facilitate digging and taking; and a part of the stalks are properly reserved, so that the carrying and soil removal operation of the root tuber in the seedling lifting process is facilitated.

Preferably, the root shoots at the top of the rhizomes are cut off at a position one fifth higher than the shoot base along the lateral axis before cutting in step 1). Cutting along the cross axis, on the one hand can guarantee that the wound area is minimum, reduces the pollution risk, prevents to rot, and on the other hand can keep more lateral buds of bud base, and for the chinese herbaceous peony, the lateral bud that is close to the rhizome, environmental tolerance ability and the ability of developing into the plant are stronger.

Preferably, the cut sections are sterilized before field planting to reduce the risk of pest infection at the wound.

Further preferably, the disinfection treatment specifically comprises the step of soaking the cut segments in a carbendazim solution for 15-20 min, wherein the volume ratio of the carbendazim to water is 1: 780-820. Naturally airing the disinfected rootstocks in a shade for 30min to ensure that no obvious water stain remains on the surface layers of the rootstocks. The operation can eliminate bacteria on wound and cut segment, and is favorable for wound healing and ensuring normal development and germination of rhizome.

Preferably, the field planting is specifically performed by making the section of the first cut parallel to the ground, making the included angle between the sections of the other cut and the ground 0-10 degrees, and burying the cut in soil. The above operation is beneficial to the bud of different parts of the rhizome cutting block to obtain the most suitable bud generation long position.

Preferably, the interval between two adjacent cutting sections is 5-10 cm, and the soil covering depth is 5-10 cm. The operation can ensure that a stable soil environment is maintained in a natural field state, and the germination is facilitated.

Preferably, watering is carried out once after 5-10 days of planting, and watering is carried out thoroughly once; watering once when the lowest temperature drops to 0 ℃ at night, and thoroughly watering once; and after the temperature rises again and the soil is thawed, removing the covering soil 3-4 cm away from the top of the root and stem, and watering once and thoroughly until the Chinese herbaceous peony sprouts. The rhizome wound can be fully healed without watering immediately after planting, and the accumulated water and the rottenness can be prevented; watering before soil is frozen in winter is favorable for improving soil humidity, so that the peony is favorable for safe overwintering. In spring, the air temperature rises again, the soil is defrosted, and the watering is favorable for the development and the germination of new roots of the rhizomes. And the excessively thick covering soil at the top of the rootstock is removed, so that the rootstock bud is prevented from being planted too deeply and failing to germinate and emerge.

Generally, the temperature is reduced to 0 ℃ in about 11 months per year, and then is increased again in the spring of the next year.

The invention has the following beneficial effects:

the cutting propagation method for the peony roots provided by the invention is simple in flow and easy to operate, breaks through the characteristics of low germination rate, variety specificity and the like of the traditional propagation method, and the obtained root and stem segments are high in germination rate and seedling rate and high in propagation efficiency, is the first attempt and practice in the peony propagation field, provides a new thought for large-scale production of peony seedlings, and has important production and application values.

Drawings

FIG. 1 shows the sub-plant morphology of conventional peony 'Dafugui' ramet in the examples of the present invention;

FIG. 2 shows the morphological structure of the peony 'Fenyunu' rhizome in the present example;

FIG. 3 shows the sprouting of the first section of the rhizome of peony "Fenyunu" according to the present invention;

FIG. 4 shows the sprouting of the second section of the rhizome of peony "Fenyunu" according to the present invention;

FIG. 5 shows the sprouting of third segment of peony in the present invention;

FIG. 6 shows the sprouting and germination of the second section of the root of peony 'Zhongshengfen' according to the present invention;

FIG. 7 shows the sprouting of the third segment of peony 'Dafugui' in the examples of the present invention.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention, but are not intended to limit the scope of the invention.

At the end of 9 months and at the beginning of 10 months, the roots and stems of the Chinese herbaceous peony which grows in the germplasm resource garden of the Mingtianshan of the national floriculture center (Beijing, Changping district, Mingtianzhen) for more than 2 years and is propagated by dividing plants are observed and sampled, at the moment, the stems and branches of the Chinese herbaceous peony on the ground are withered, and the root and stem buds are formed.

The plants involved in the examples developed normally, the rootstocks grew vigorously, and no obvious diseases and insect pests existed. The scope of protection of the invention is not limited to these examples.

Example 1

The embodiment relates to a method for propagating Chinese herbaceous peony by rhizome, which comprises the following steps: the peony variety referred to in this example is 'Fenyunu',

1) obtaining the normally developed roots of the Chinese herbaceous peony: pruning the peony stalks at a position which is about 10cm away from the ground surface by using a pruning shear, and completely digging underground parts of the peony stalks at a position which is about 20cm away from the stalks by using a stainless steel fork, so as to prevent the stalks from being damaged in the seedling raising process and ensure the complete structure of the stalks. And (3) placing the dug peony soil balls in a shade place for airing for 30min, wherein the surface soil is basically aired and is easy to shake off, and the roots and stems have certain toughness due to partial dehydration and are not easy to break in the soil knocking and carrying processes. Judging the growth direction of the rhizome according to the growth direction of the stem, slightly separating the rhizome at different positions in sequence according to the growth characteristics of the rhizome to expose fleshy roots, shearing the fleshy roots on the rhizome along the joint of the fleshy roots and the rhizome by using pruning shears, and cutting quickly to ensure that the wound is smooth.

And transversely cutting the top of the rootstock at a position 2-5 cm below the rootstock bud base part of the rootstock into a first cutting segment along the longitudinal axis direction of the rootstock by using a cutter, transversely cutting the part 2-5 cm below the cutting position of the first cut rootstock into a second cutting segment, transversely cutting the part 2-5 cm below the cutting position of the second cut rootstock into a third cutting segment, and continuously cutting the first cutting segment and the second cutting segment in the above manner until all the rest rootstocks are cut. In the first cutting, the upper part of the bud is cut off from the bud base at a position one fifth higher than the bud base in a direction perpendicular to the longitudinal axis of the bud.

2) Cutting, soaking and sterilizing: preparing a 1:800 carbendazim aqueous solution, placing the obtained rhizome cutting tissue in the aqueous solution, soaking for 15-20 min, and airing in a cool place until no obvious water stain is visible on the surface of the rhizome.

3) Planting in a field: during planting, the surfaces of the cut parts of the rootstocks are placed at an angle of 0-10 degrees with the ground, preferably, the cut parts are placed in parallel with the ground, when the first cut parts with rootstock buds are planted, the cut parts are parallel with the ground, the bud ends face upwards, the rootstock cut parts are planted at intervals of 5-10 cm in pairs, and the soil covering depth is 5-10 cm.

Watering once after planting for 5-10 days, and thoroughly watering once. The rootstocks are in a moist soil environment, which is favorable for rooting and sprouting. When the temperature is reduced to about 0 ℃ at the bottom of 11 months, watering once, and watering thoroughly once, so that the rootstocks can be prevented from cold and overwinter; in spring of the next year, after the temperature rises again and the soil is thawed, removing the top of the rhizome and removing 3-4 cm of covering soil to prevent the buried soil from being too deep to influence the development and germination of the sprout. Watering once, watering thoroughly once, providing sufficient water, and maintaining the growth demand of the bud until the bud germinates.

The growth status of the plants of this example is shown in FIGS. 2-5.

Example 2

The difference from example 1 is that the variety referred to in this example is 'Dafugui'. The growth status of the plants of this example is shown in FIGS. 1 and 7.

Example 3

The difference from example 1 is that the species referred to in this example is 'Zhongshengfen'. The growth status of the plants of this example is shown in FIG. 6.

Comparative example 1

Compared with the example 1, the method has the difference that the rhizome is directly planted and managed without sterilizing the cut section after being cut, but part of the rhizome wound is rotten and can not root and sprout because of germ infection.

In order to compare with the traditional plant division propagation mode, according to the size of the plant cluster of each peony variety, the number of buds and the natural growth problem of rhizomes, the statistics is carried out according to 3-4 buds of one sub-plant and 2 thicker fleshy tuberous roots (see table 1), the number of theoretical molecular plants of each plant is obtained through calculation, and the propagation coefficient is calculated.

TABLE 1

The method for calculating the number of the theoretical molecular strains comprises the following steps: theoretical number of molecular plants (number of plant buds before division/number of sub-plant buds) × number of plants

The method for calculating the propagation coefficient of the theoretical sub-plant comprises the following steps: theoretical seed plant propagation coefficient is theoretical numerable plant number/plant number

The method for calculating the rhizome propagation coefficient comprises the following steps: rhizome propagation coefficient is equal to the number of stem segments/plant number

As can be seen from Table 1, the propagation coefficient of Paeonia lactiflora can be significantly increased by using rhizome segments for propagation, and the propagation coefficient of each variety in each embodiment can be increased to at least 8 times that of the conventional plant division method by using the method provided by the invention.

Fig. 2 to 7 show the germination and emergence conditions of the buds of different rhizome segments of different varieties of paeonia lactiflora in this embodiment, and it can be clearly seen from the figures that each rhizome segment has multiple buds germinating and emerging, thereby further confirming the feasibility and reliability of the paeonia lactiflora rhizome cutting propagation method of the present invention.

From the perspective of germination, part of the rhizome can germinate at a plurality of parts of the rhizome segment part at the same time, which shows that the propagation coefficient obtained by the method has a larger space for improvement, and the inventor is continuing to search for optimization of peony rhizome cutting mode on the basis.

Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims (9)

1. A method for propagating Chinese herbaceous peony through rootstocks is characterized by comprising the following steps:

1) cutting the root and stem of Paeonia lactiflora into multiple segments;

2) carrying out field planting on the cut sections;

the rootstock is intercepted by the following method: digging out the underground part of the peony completely, judging the growth direction of the rhizome according to the growth direction of the stems of the overground part, dividing the underground part along the growth direction of the rhizome, keeping the rhizome intact in the dividing process, and removing fleshy roots attached to the rhizome to obtain the peony root-bark cutting machine;

the specific cutting method of the cut segments comprises the steps of cutting a root bud at the top of a rhizome by taking the bud base of the root bud as a starting point and 2-5 cm below the bud base to obtain a first cut segment, and then continuing cutting, wherein the length of each cut segment is 2-5 cm, and the cutting of the rhizome is completed until all the cut segments are cut;

the rootstock grows downwards along the stem, and the growth direction of the rootstock is the growth direction of the rootstock when the rootstock is extended downwards along the direction of the overground stem.

2. The method as claimed in claim 1, wherein the cutting is performed in a direction perpendicular to the longitudinal axis of the rhizome.

3. The method according to claim 1 or 2, wherein the rhizomes are taken from plants more than 2 years after the ramet propagation.

4. The method of claim 1, wherein the rhizomes are cut at 9-10 months.

5. The method as set forth in claim 1 or 4, wherein the shoot buds at the top of the rootstocks are cut off at a position one fifth higher than the bud base along the lateral axis at the top of the buds before cutting in step 1).

6. The method of claim 1, wherein the cut pieces are sterilized prior to field planting.

7. The method as claimed in claim 6, wherein the disinfection treatment is carried out by soaking the cut segments in a carbendazim solution for 15-20 min, wherein the volume ratio of the carbendazim to water is 1: 780-820.

8. The method according to claim 1 or 6, wherein the field planting is performed by arranging the section of the first segment to be parallel to the ground, arranging the sections of the other segments to have an angle of 0-10 ° with the ground, and burying the segments in the soil;

and/or the interval between two adjacent cutting sections is 5-10 cm, and the soil covering depth is 5-10 cm.

9. The method of claim 8, wherein the water is applied once and thoroughly after 5-10 days of planting; when the lowest temperature is reduced to 0 ℃ at night, watering once in the daytime, and thoroughly watering once; and after the temperature rises again and the soil is thawed, removing the covering soil 3-4 cm away from the top of the root and stem, and watering once and thoroughly until the Chinese herbaceous peony sprouts.

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