Method for rapidly creating new winter wheat breeding germplasm of six generations in one year

Abstract

The invention discloses a method for creating a new winter wheat rapid breeding seed and application thereof, according to the method, a wheat specific germplasm SN0594 which does not need vernalization and is short in growth cycle is used as a parent and is applied to the creation process of a wheat character rapid stabilizing material, and the problems of long time, large loss, easy damage and the like in the winter wheat character stabilizing process can be solved. The method for rapidly creating the stable population by using the wheat SN0594 comprises the following steps: selecting a population parent, and hybridizing the population parent with the wheat germplasm SN0594; performing selfing generation adding in a culture room to obtain an F2 group; performing phenotype identification and screening on the F2 generation in a culture room; and performing culture room selfing generation acceleration to obtain a stable material. According to the method, the breeding frequency of the winter wheat in one year can be increased, a rapid and efficient method is provided for rapidly stabilizing the characters of the winter wheat, a test material with a short growth cycle is provided for indoor tests such as wheat genetic transformation, and the application range of the winter wheat in the indoor tests is widened.

Description

Technical Field

[0001] The invention belongs to the technical field of agriculture, and specifically relates to a method for rapidly creating new winter wheat breeding germplasm for six generations in one year and an application thereof. Background Art

[0002] For indoor experiments such as transgenic functional verification, combining with speed breeding technology (Speed ​​Breeding) can shorten the test cycle. The temperature and light controllable artificial climate chamber provided by the current rapid breeding technology has greatly accelerated the growth process of wheat, but the selection of rapid breeding germplasm is relatively narrow, generally spring wheat that does not require vernalization. Winter wheat is not considered due to its long vernalization time. For example, the spring-biased Fielder is often used as a genetic transformation material. Although Fielder does not require vernalization, it has a long growth cycle, the heading period in the growth room is about 60 days, and the agronomic traits are average. The long vernalization time limits the application of winter wheat materials and prolongs the cultivation time of stable winter wheat strains. It is urgent to improve winter wheat materials, speed up the creation of stable winter wheat strains, and broaden the application scope of winter wheat materials in indoor experiments. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned existing problems and provide a method for quickly creating new winter wheat breeding germplasm with six generations per year and its application. The method can shorten the generation stability time and improve the efficiency of creating stable strains. New wheat germplasm that does not require vernalization, has a short growth cycle and good agronomic traits is obtained. The germplasm can accelerate the speed of creating stable winter wheat strains and shorten the cycle of indoor experiments such as wheat genetic transformation and gene function identification.

[0004] The specific technical solutions are as follows:

[0005] The present invention provides a method for rapidly creating new winter wheat breeding germplasm in six generations per year, comprising the following steps:

[0006] Step 1. Select winter wheat material A and cross it with wheat germplasm SN0594 carrying the vernalization dominant gene

[0007] In October, the selected winter wheat material A and wheat germplasm SN0594 were planted in the field in autumn. According to the investigation results of the flowering period of the parents, the sowing date of parent A and SN0594 was arranged in time to ensure that the flowering period of the parents coincided when hybridization was performed; during the flowering period of wheat, parent A and SN0594 were hybridized, and the hybrid ears were harvested, threshed, and grains were harvested in June of the first year when the wheat matured;

[0008] Step 2. Self-crossing in the culture room to produce F2

[0009] The F1 grains obtained in step 1 are germinated at room temperature, and the germinated seeds are sown in a seedling pot with a diameter of 30 cm and a height of 20 cm containing a substrate, 6 seeds are sown in each pot, and placed in a culture room at 25°C, with a light duration of 22 hours per day, a light intensity of greater than or equal to 600 Lux, and a humidity of 60-70%, and watering is paid attention to during the growth period; about 20-25 days after flowering, the ears are harvested, and the harvested ears are placed in a drying room at 55°C for 10-12 hours, and the progeny F2 is obtained by manual threshing; the entire step 2 takes about 2 months;

[0010] Step 3. Phenotypic screening of the F2 generation in the culture room

[0011] In August of the first year, the F2 grains obtained in step 2 are planted in a culture room; the seeds are germinated at room temperature, and the germinated seeds are directly sown into a 96-well culture plate containing a substrate without vernalization treatment, with one seed sown in each well, and the culture conditions are the same as those in step 2; individual plants with a short heading period and good agronomic traits are selected for marking with a card, and the marked ears are harvested about 20-25 days after flowering; the progeny F3 that does not require vernalization, has a short heading period, and has good agronomic traits is obtained;

[0012] Step 4. Self-crossing in the culture room accelerates the acquisition of stable materials

[0013] According to the phenotypic identification method of the F2 population in step 3, after obtaining F3, use the same method to obtain F4, F5, ...; each generation takes about 2 months, and 6 generations can be completed within a year, shortening the 6-year field self-pollination stabilization time to one year, and the F7 generation can be obtained in June of the second year. The F7 generation has met the basic requirements for stable material generations, and can be directly used for gene function identification, genetic transformation and other experiments in the growth room.

[0014] Preferably, in step 1, each hybrid ear is ensured to have at least 10 spikelets.

[0015] Preferably, in step 1, the F2 population generated for phenotypic screening has a number of hybrid ears of no less than 3.

[0016] Compared with the prior art, the present invention has significant beneficial effects:

[0017] The method of the present invention can avoid the vernalization stage of winter wheat, shorten the stable years of wheat strains, shorten the acquisition of stable strains from 6 years to the current 1 year, create new germplasm materials for rapid breeding of winter wheat, and be used for research such as rapid identification of gene functions indoors. Using this method, we hybridized SN0594 with winter materials SN34, Yannong 15, etc., and obtained stable strains in a relatively short period of time. The stable strains have the characteristics of no need for vernalization, short growth cycle, and excellent agronomic traits. This proves the feasibility of the method. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of hybridizing winter material SN34 with wheat germplasm SN0594 to obtain a stable strain. DETAILED DESCRIPTION

[0019] The following uses SN34 as a parent example and further illustrates the technical solution of the present invention in conjunction with the accompanying drawings.

[0020] Step 1: Hybridize SN34 with wheat germplasm SN0594 to obtain F1

[0021] SN34 is a winter material that requires 8 weeks of vernalization before entering the reproductive growth stage, but it has excellent agronomic traits, large ears and many grains, and a relatively low plant height; SN0594 is a material carrying the vernalization dominant gene Vrn-A1a, which does not require vernalization and has a short growth cycle, but has poor agronomic traits and a relatively high plant height.

[0022] The results of the early flowering period survey showed that SN34 bloomed earlier, about 10 days earlier than SN0594. In October, the parent SN34 and SN0594 were planted in the field. SN34 was sown in 4 batches, with an interval of about 1 week between each batch.

[0023] During the flowering period of wheat, hybridization is performed using SN34 as the female parent and SN0594 as the male parent, or using SN34 as the male parent and SN0594 as the female parent.

[0024] The subsequent work is to construct an F2 population for phenotypic identification and screening. The population size needs to be around 300, with a total of 2 hybrid ears. Each emasculated ear must have at least 10 spikelets, and about 20 hybrid grains must be obtained.

[0025] In June of the first year, hybrid ears are harvested when the wheat matures and threshed manually.

[0026] Step 2: Self-crossing in the culture room to produce hybrid F2

[0027] The hybrid seeds (F1) obtained in step 1 are germinated at room temperature (25°C), sown in a seedling pot with a diameter of 30 cm and a height of 20 cm containing a substrate, and 6 seeds are sown in each pot. They are placed in a culture room at 25°C, with a light duration of 22 hours per day, a light intensity greater than or equal to 600 Lux, and a humidity of 60-70%. Pay attention to watering during the growth period, and harvest the ears about 20-25 days after flowering, when the grains are green to a certain extent. The harvested ears are placed in a drying room at 55°C for 10-12 hours, and threshed manually to obtain the progeny F2. This step takes a total of 2 months, during which time pay attention to pests and diseases such as aphids and powdery mildew.

[0028] Step 3: Phenotypic screening of the F2 generation in the culture room

[0029] When constructing the F2 population, the number of F2 obtained in step 2 is about 400, and about 360 plants will eventually survive.

[0030] According to this step, it can be completed before August of the same year. The next step is to investigate and screen the indoor heading period and agronomic traits of F2. Plant F2 in August and germinate at room temperature. The germinated seeds are directly sown into a 96-well culture plate containing a matrix without vernalization treatment. One seed is sown in each well. The culture conditions are the same as step 2; select individual plants with a short heading period and good agronomic traits for card marking, and harvest the marked ears about 20-25 days after flowering. According to the calculation of the heading: non-heading ratio of 3:1 in the F2 generation, about 270 Vrn-A1a dominant vernalization gene individual plants can be obtained, and then select individual plants with excellent agronomic traits from them, and about 135 F3 progeny plants that do not require vernalization, have a short heading period, and have good agronomic traits are obtained.

[0031] Step 4: Self-crossing and generation in the culture room to accelerate the acquisition of stable materials

[0032] According to the phenotypic identification method of the F2 population in step 3, after obtaining F3, use the same method to obtain F4, F5, ...; each generation takes about 2 months, 6 generations can be obtained in a year, and F7 grains can be obtained in June of the second year. The F7 generation has met the basic requirements for stable material generations and can be used for subsequent genetic transformation experiments.

[0033] Figure 1 This is a schematic diagram of hybridization between SN34 and wheat germplasm SN0594 to create new germplasm.

[0034] The Vrn gene is a vernalization gene. When the genotype is Vrn / Vrn or Vrn / vrn, heading can be produced without vernalization. When the genotype is vrn / vrn, vernalization is required for heading to occur.

[0035] The above is only a preferred implementation of this patent. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of this patent. These improvements and substitutions should also be regarded as the scope of protection of this patent.

Claims

1. A method for rapidly creating new winter wheat breeding germplasm in six generations per year, characterized in that: The following steps are involved: 1) Select winter wheat material A and wheat germplasm SN0594 carrying the vernalization dominant gene for hybridization: Winter wheat material A and SN0594 were sown in batches in the field, and the sowing time was adjusted to make the flowering periods of the parents coincide; hybridization was completed during the flowering period, and F1 grains were harvested during the maturity period; (2) Self-crossing in the culture room to produce the F2 population: After germination, the F1 seeds were sown in seedling containers and cultured at 25°C, 22 hours of light per day, light intensity ≥ 600 Lux, and 60-70% humidity. The F2 seeds were harvested 20-25 days after flowering. (3) F2 representative phenotype screening: The F2 grains were directly planted in the culture room without vernalization, and the individual plants with short heading period and good agronomic traits were selected to harvest the F3 grains; (4) Accelerate the acquisition of stable materials: Repeat the cultivation and screening of step (3) for F3 and subsequent generations, each generation taking about 2 months, and continuously self-pollinate to F7 to obtain stable materials.

2. The method according to claim 1, characterized in that: In step (1), at least 10 spikelets are retained for each hybrid ear.

3. The method according to claim 1, characterized in that: In step (1), the number of hybrid ears is not less than 2.

4. Use of the method according to any one of claims 1 to 3 in creating superior winter wheat varieties.

5. Use of the method according to any one of claims 1 to 3 in shortening the winter wheat breeding cycle.

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