CN109362505B

CN109362505B - Method for rapidly adding generations of non-heading Chinese cabbages

Info

Publication number: CN109362505B
Application number: CN201811553171.1A
Authority: CN
Inventors: 高长斌; 汪爱华; 宋莉萍; 王斌才
Original assignee: Wuhan Academy of Agricultural Sciences
Current assignee: Wuhan Academy of Agricultural Sciences
Priority date: 2018-12-18
Filing date: 2018-12-18
Publication date: 2021-06-11
Anticipated expiration: 2038-12-18
Also published as: CN109362505A

Abstract

The invention discloses a method for quickly adding generations of non-heading Chinese cabbages, which comprises the following steps: vernalizing the germinated seeds at 2-4 ℃ for 15-25 days, transplanting the seeds to a greenhouse, culturing the seeds in a full-spectrum LED lamp tube under full-day illumination, controlling the plant type by removing peripheral old leaves and rosette leaves after the plants grow buds, pollinating mature buds on the outermost periphery of inflorescence after the flowers of the main bolt are opened, stripping seed coats of immature seeds after pollination to break dormancy, and entering the next generation after seeding. The method can greatly accelerate the breeding process of new varieties of the non-heading Chinese cabbage and realize at least one 4-generation breeding generation of the non-heading Chinese cabbage.

Description

Method for rapidly adding generations of non-heading Chinese cabbages

Technical Field

The invention belongs to the field of crop breeding, and particularly relates to a novel method for realizing rapid generation addition of non-heading Chinese cabbages in a greenhouse.

Background

Non-heading Chinese cabbage is a two-year-old cruciferous vegetable, and can only breed one generation in one year under natural conditions. In the breeding process, it generally takes 6-8 years to breed a self-bred line, while it takes longer to breed a hybrid. In order to improve the breeding efficiency of the non-heading Chinese cabbage, the growth cycle is urgently needed to be shortened, and a fast generation method is explored. Previous attempts have been made to breed non-heading Chinese cabbage materials by means of cross-breeding, winter greenhouse seed collection, tissue culture and the like, but these methods only achieve the breeding efficiency of 1.5-2 generations in a year. The reason for this is that the growth period of the non-heading Chinese cabbage is long, the nutrition growth stage needs to be influenced by vernalization, the later stage needs to induce high temperature and long day for normal flowering, and even the mature seeds have strong dormancy, so the superposition of these factors influences the improvement of the propagation efficiency of the non-heading Chinese cabbage.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a method for rapidly adding generations of non-heading Chinese cabbages by utilizing a greenhouse, and the method can greatly accelerate the breeding process of new varieties of the non-heading Chinese cabbages. According to the method, germinating seeds are vernalized in an environment of 2-4 ℃, then are transplanted under an LED lamp tube of a full spectrum of a greenhouse for 24-hour continuous illumination, the plant type and the pollination mode are controlled in the culture process, seed coats of immature seeds are peeled off 25 days after pollination to break dormancy, and the next generation is started after seeding.

In order to achieve the purpose, the invention is realized by the following technical scheme:

(1) seed germination and vernalization

Selecting plump seeds, placing into a culture dish, adding water for germination, placing into a refrigerator at 2-4 deg.C for 15-25 days after the seeds germinate, performing incomplete vernalization treatment, and keeping the germinated seeds in a humid environment.

(2) Plant cultivation

Transplanting the vernalized seeds to a greenhouse, sowing the seeds in nutrient soil, placing the seeds on a tissue culture rack, and culturing the seeds under the irradiation of a full-spectrum LED lamp tube with the spectral band of the lamp tube between 340 and 800nm by illumination all day. During the culture period, nutrient solution is supplemented every two days.

(3) Plant type control

After the buds of the plants appear, the peripheral old leaves are removed, all rosette leaves are removed after bolting, the growth of the side bolts is inhibited, and finally, only the main bolts of the plants flower.

(4) Pollination treatment

When 3-4 flowers of the main bolt of the plant are opened, the mature bud at the outermost periphery of the inflorescence is subjected to artificial bud stripping and selfing or stamen removal hybridization, so that the mature bud is normally seeded. After 5-7 days, removing immature buds on inflorescence after the buds around the outmost part of inflorescence can generate extended siliques.

(5) Seed harvesting and dormancy breaking

When pollination is successful and the siliques begin to elongate, all leaves on the plants are removed and the siliques are retained only to speed up seed maturation, Hoagland's nutrient solution is replenished once a week. After pollination for 25 days, the siliques were removed, the seed coats were removed and sown on petri dishes to start the next generation of propagation.

Preferably, the vernalization treatment time in step 1) is 15-20 days.

Preferably, the ambient temperature of the greenhouse is controlled between 24 and 26 ℃.

Compared with the prior art, the invention has the following advantages and beneficial effects:

according to the growth habit of the non-heading Chinese cabbage, the method comprehensively utilizes various technical means to overcome the influence of factors such as vernalization, illumination, temperature, plant types, seed dormancy and the like on plant development, finally realizes the rapid generation-adding propagation of the non-heading Chinese cabbage and greatly improves the breeding efficiency. Of the tested materials, the strong winter material 'QR 2' required only 102 days to complete the growth period, and the weak winter material 'hanyou' required less time, up to 69 days. Therefore, the method provided by the invention can realize the breeding generation of the non-heading Chinese cabbage for at least 3-4 generations in one year.

Drawings

FIG. 1 shows the transplanted seedlings of Chinese cabbage.

FIG. 2 shows the cultivation of non-heading Chinese cabbage in greenhouse.

FIG. 3 shows non-heading Chinese cabbage in bud stage.

FIG. 4 shows non-heading Chinese cabbage in flowering period

Detailed Description

The present invention will be described in more detail with reference to examples.

The non-heading Chinese cabbage used in this example was prepared in two parts: one part is selfing line 'QR 2' (selected from vegetables of the agricultural academy of Wuhan City) with strong winterness, and the other part is variety 'Hanyou' (selected from vegetables of the agricultural academy of Wuhan City) with weak winterness.

1. Seed treatment

1.1 seed germination: respectively selecting 20 full seeds of non-heading Chinese cabbage material QR2 and Hanyou, placing into a culture dish, respectively, laying a layer of filter paper on the bottom of the dish, and adding a little pure water to make the seeds fully imbibe without affecting the respiration. The petri dish was placed in an incubator at 25 ℃ and the seed germination state was observed.

1.2 vernalization time test: after 2 days, white buds were exposed from the seeds of 'QR 2' and 'hanyou', but cotyledons were not developed yet, and the seeds were put into a refrigerator, the temperature of the refrigerator was adjusted to 2 ℃, and the treatment time was set to 8 days, 15 days, and 25 days, respectively, during which light irradiation was not required. As a result, it was found that the longer the vernalization treatment time was, the shorter the time required for bolting and flowering of the material was. In conjunction with the time of vernalization in the refrigerator, we conclude that a 15 day time period of vernalization minimizes the growth period of the plants (table 1).

TABLE 1 growth period of non-heading Chinese cabbage treated at different vernalization times

2. Plant planting

2.1 sowing: after the vernalization process, the seeds of 'QR 2' and 'hanyout' both exposed two cotyledons due to low temperature growth, but did not fully spread. Seeds of the two materials were sown into nutrient soil (purchased from wuhanriqing biotechnology) separately, one seed was placed in each nutrition pot, and watered to grow normally. And placing the nutrition pot on a tissue culture frame to enable the nutrition pot to be under the irradiation of a lamp tube.

2.2 illumination test:

in order to determine the optimal illumination condition capable of promoting the plant to bloom, experiments are carried out aiming at the light quality and the illumination length, seeds of 'QR 2' and 'Hanyou' after vernalization for 15 days are respectively placed on a tissue culture rack consisting of 4 incandescent lamp tubes (with the power of 36W) and 4 LED full spectrum lamp tubes (customized from Shandong Guixiang photoelectricity Limited company, the light quality is adjusted to be full spectrum, the spectrum wave band is between 340 nm and 800nm, and the power is 36W). The illumination time was then set to 3 gradients of 12 hours, 16 hours and 24 hours respectively under two illumination conditions, the ambient temperature of the greenhouse being controlled at 25 ℃. The results show that (table 2), the QR2 and the Hanyou have the same illumination sensing characteristics, and the growth period of the LED full-spectrum lamp tube is shorter than that of an incandescent lamp under the same illumination time, which indicates that the LED full-spectrum lamp tube can better promote the flowering of the non-heading Chinese cabbage. Meanwhile, under the same light quality condition, the longer the illumination time is, the shorter the growth period of the plant is. Therefore, the growth period of the non-heading Chinese cabbage can be shortened to the greatest extent by determining plants under the 24-hour continuous illumination condition of the LED full-spectrum lamp tube.

TABLE 2 growth period of non-heading cabbage (time from sowing to flowering) under different light quality and illumination conditions

2.3 plant culture: after the seeds are germinated, the seeds are placed on a culture rack consisting of LED lamp tubes and continuously illuminated for 24 hours until the seeds are harvested. During the culture period, Hoagland's nutrient solution (the formula is 945mg/L calcium nitrate, 607mg/L potassium nitrate, 115mg/L ammonium phosphate, 493mg/L magnesium sulfate, 2.5ml/L ferric salt solution, 5ml/L trace elements and 6.0 pH value, wherein the ferric salt solution comprises 2.78g ferrous sulfate heptahydrate, 3.73g disodium ethylene diamine tetraacetate and 500ml distilled water, the pH value is adjusted to 5.5, the trace element solution comprises 0.83mg/L potassium iodide, 6.2mg/L boric acid, 22.3mg/L manganese sulfate, 8.6mg/L zinc sulfate, 0.25mg/L sodium molybdate, 0.025mg/L copper sulfate and 0.025mg/L cobalt chloride) is supplemented every two days, and the environmental temperature of the greenhouse is controlled at 25 ℃.

3. Plant type control

After the plant buds, the old leaves at the periphery are removed to prevent the plant from overgrowing, and the plant is indicated to enter the reproductive growth stage. Subsequent statistical results show that all plants of the materials 'QR 2' and 'hanyou' were able to bolt normally in the greenhouse, with the average time from sowing to bolting of 'QR 2' being 48.5 days and the average time from sowing to bolting of 'hanyou' being 21.4 days. Removing all rosette leaves of the plants at the bolting stage, inhibiting the growth of side bolts, and finally enabling only main bolts of the plants to bloom; when the time from sowing to flowering of the plants was investigated after the first flower was opened, it was found that ` QR2 ` required 62.1 days, while ` Hanyou ` required 28.7 days (Table 1, Table 2).

4. Pollination treatment

When 3-4 flowers of the main bolt of the plant are opened, the mature bud at the outermost periphery of the inflorescence is subjected to artificial bud stripping and selfing, so that the mature bud can normally seed and is marked. Meanwhile, immature buds on the inflorescence are reserved, so that the peripheral mature buds can not generate seeds. After 5-7 days, all immature buds on the inflorescence are removed after the most peripheral mature buds of the inflorescence can generate extended siliques.

5. Seed harvesting and dormancy breaking

When pollination is successful and the siliques begin to extend, all leaves on the plants are removed, the siliques are only retained to accelerate the maturity of the seeds, meanwhile, the supply of Hoagland's nutrient solution is stopped, and a small amount of water is supplemented every 5 days to keep the plants in a relatively dry environment. After 25 days of pollination, the siliques were removed, the seed coats were removed and sown on petri dishes. After 2-3 days, the seeds germinate and cotyledons begin to grow out, and the seeds are placed in a refrigerator for vernalization and the next generation of propagation begins.

Of the tested materials, the strong winter material 'QR 2' required only 102 days to complete the growth period, and the weak winter material 'hanyou' required less time, up to 69 days. Therefore, the method provided by the invention can realize the breeding generation of the non-heading Chinese cabbage for at least 3-4 generations in one year.

Claims

1. A method for rapidly adding generations of non-heading Chinese cabbages is characterized by comprising the following steps:

1) seed germination and vernalization

Selecting plump seeds, placing the seeds into a culture dish, adding water for germination, placing the seeds into a refrigerator at 2 ℃ for treatment for 15 days after the seeds germinate, and performing incomplete vernalization treatment;

2) plant cultivation

Transplanting the vernalized seeds to a greenhouse, sowing the seeds into nutrient soil, placing the seeds on a tissue culture frame, continuously illuminating and culturing the seeds under a full-spectrum LED lamp tube for 24 hours, wherein the spectrum band is between 340 and 800nm, and supplementing Hoagland's nutrient solution every two days during the culture period;

3) plant type control

After the buds of the plants appear, removing peripheral old leaves, removing all rosette leaves after bolting, inhibiting the growth of side bolts, and finally enabling the plants to flower only the main bolts;

4) pollination treatment

When 3-4 flowers of the main bolt of the plant are opened, manually stripping the mature buds at the outermost periphery of the inflorescence for selfing or removing stamens for hybridization to ensure that the flowers normally seed, and after 5-7 days, removing immature buds on the inflorescence after the mature buds at the outermost periphery of the inflorescence can generate extended siliques;

5) seed harvesting and dormancy breaking

When pollination is successful and the siliques begin to extend, removing all leaves on the plants, only keeping the siliques to accelerate the maturity of seeds, simultaneously stopping the supply of Hoagland's nutrient solution, supplementing water at intervals, taking down the siliques 25 days after pollination, removing seed coats of the seeds, sowing the seeds on a culture dish, and starting the propagation of the next generation.

2. The method for rapid generation of non-heading Chinese cabbage according to claim 1, wherein the temperature of the greenhouse is controlled to 24-26 ℃.