Breeding method of velvet-free low-phenol limited-fruit-branch cotton

Abstract

The invention belongs to the technical field of cotton cultivation, and particularly relates to a method for breeding velvet-free low-phenol limited fruit branch cotton, which comprises the following steps: S1, preparing bright-seed velvet-free cotton-free No.1 and dominant low-phenol cotton to hybridize to obtain an F1 generation; s2, selfing the F1 generation, and stopping selfing until the next generation has no velvet and low-phenol characters and does not separate, so as to obtain velvet-free low-phenol cotton; s3, hybridizing the velvet-free low-phenol cotton and the limited-fruit-branch cotton to obtain a G1 generation; and S4, selfing the generation G1 to obtain a velvet-free, low-phenol and limited-fruit-branch G2A generation and a velvet-free, low-phenol and limited-fruit-branch G2B generation, and continuously selfing the G2A generation for multiple times by taking the velvet-free, low-phenol and limited-fruit-branch as target characters until stable velvet-free, low-phenol and limited-fruit-branch cotton is obtained. The SGK321 cotton is subjected to variety improvement, the yield of the SGK321 cotton is increased and the toxicity content of gossypol is reduced on the premise that the advantages of the SGK321 cotton are reserved, and the SGK321 cotton is more in line with the market demand.

Description

Technical Field

[0001] The invention belongs to the technical field of cotton cultivation, and in particular relates to a breeding method for lint-free, low-phenol and limited fruit-branch cotton. Background Art

[0002] SGK321 cotton is one of the world's first BT+CpTI bivalent gene insect-resistant cotton varieties. It not only has good insect resistance and high productivity, but also has good adaptability and is resistant to Fusarium wilt and Verticillium wilt.

[0003] The characteristics of SGK321 cotton are short lint, normal cottonphenol and unlimited fruit branches. However, in order to increase cotton yield, facilitate field management and meet market needs, it is necessary to cultivate lint-free, low-phenol and limited fruit branch cotton with SGK321 cotton as one of the parents while retaining the advantages of SGK321 cotton itself. Summary of the invention

[0004] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a breeding method for lint-free, low-phenol, limited fruit-branch cotton. The present invention improves the SGK321 cotton variety, improves its yield and reduces the toxicity content of cottonphenol while retaining the advantages of SGK321 itself, which is beneficial to the comprehensive utilization of cotton and better meets market demand.

[0005] The specific technical solution adopted by the present invention is:

[0006] A breeding method for lint-free, low-phenol, limited-fruit-branch cotton comprises the following steps:

[0007] S1, preparing the bare-seed and lint-free cotton-free No. 1 and hybridizing it with dominant low-phenol cotton to obtain the F1 generation;

[0008] S2, self-pollinating the F1 generation until the next generation of lint-free and low-phenol traits do not separate, then stopping self-pollination and obtaining lint-free and low-phenol cotton;

[0009] S3, hybridizing lint-free low-phenol cotton with limited fruit-branch cotton to obtain the G1 generation;

[0010] S4. Self-pollinate the G1 generation to obtain the G2A generation with no lint, low phenol, and limited fruit branches and the G2B generation with no lint, low phenol, and unlimited fruit branches. Self-pollinate the G2A generation multiple times continuously with no lint, low phenol, and limited fruit branches as the target traits until stable cotton with no lint, low phenol, and limited fruit branches is obtained.

[0011] The method for obtaining the No. 1 cotton-free product comprises the following steps:

[0012] S101, planting SGK321 cotton until a mutant with bare seeds and no lint is selected;

[0013] S102, self-pollinating the seedless and lint-free mutant for at least two consecutive years to obtain a cotton-free No. 1 with a stably inherited lint-free trait;

[0014] Planting SGK321 cotton in step S101 includes the following steps:

[0015] A. Building a breeding greenhouse, wherein the top and the periphery of the breeding greenhouse are covered with black sunshade cloth to block ultraviolet rays, and a light that does not generate ultraviolet rays is arranged in the breeding greenhouse;

[0016] B. Soak SGK321 cotton seeds in the catalyst for 30-60 minutes, dry them in the sun and sow them in the breeding greenhouse;

[0017] C. During the germination period, the temperature of the breeding greenhouse is maintained at 22-28°C, the soil humidity is 65-75%, and the air humidity is 70-80%;

[0018] D. Seedling stage, during which the temperature of the breeding greenhouse is maintained at 28-30℃, the soil humidity is 45-55%, and the air humidity is 80-90%;

[0019] E. Bud stage, during which the temperature of the breeding greenhouse is maintained at 30-35°C, the soil moisture is 45-55%, and the air humidity is 80-90%;

[0020] F. Flowering and boll forming period, during which the temperature of the breeding greenhouse is maintained at 30-32°C, the soil moisture is 45-55%, and the air humidity is 80-90%;

[0021] G. During the boll opening period, the temperature in the breeding greenhouse is maintained at 35-38°C, the soil moisture is 45-55%, and the air humidity is 70-80%.

[0022] The preparation method of the catalyst is as follows: 75-85 mg of gibberellin, 80-100 μl of brassinolide and 10-20 μmol of flavonoids are added into each liter of water, and the mixture is stirred evenly to obtain the catalyst.

[0023] Base fertilizer is applied to the soil in the breeding greenhouse, and the base fertilizer includes 2.8-3kg / mu of nitrogen fertilizer, 5-6.5kg / mu of phosphorus fertilizer, and 2.8-3kg / mu of potassium fertilizer.

[0024] The beneficial effects of the present invention are:

[0025] 1. In the present invention, the lint-free mutant of SGK321, No Cotton 1, is first hybridized with dominant low-phenol cotton to obtain lint-free, low-phenol cotton with stable traits, and then the lint-free, low-phenol cotton is hybridized with limited fruit branch cotton to obtain lint-free, low-phenol, limited fruit branch cotton with stable traits. The present invention improves the SGK321 cotton variety, increases its yield and reduces the cottonphenol toxicity content while retaining the advantages of SGK321 itself, and is more in line with market demand.

[0026] 2. The lint-free mutant of SGK321, Wumian No. 1, is difficult to obtain. Under natural planting conditions, the probability of SGK321 mutating toward lint-free is extremely low. Therefore, the present invention increases the probability of lint-free mutation of cotton by controlling environmental variables.

[0027] First of all, one of the functions of short lint is to block part of the ultraviolet rays. Therefore, the present invention uses a sunshade cloth to reduce the ultraviolet radiation to which the cotton is exposed, and uses a light lamp without ultraviolet rays to make up for the daily lighting time required for the cotton. By reducing the demand of cotton for short lint, the probability of cotton suddenly changing from lint-containing to lint-free is increased.

[0028] Secondly, one of the other functions of short lint is to promote plant transpiration by increasing the plant surface area. Therefore, this step controls environmental variables to keep the cotton in a high temperature and relatively water-deficient state during its growth process, so that the cotton itself needs to reduce transpiration, that is, the plant needs to inhibit the formation of short lint to increase the probability of cotton mutating from lint to no lint. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. 1. Specific embodiments

[0031] A breeding method for lint-free, low-phenol, limited-fruit-branch cotton comprises the following steps:

[0032] S1, preparing the bare-seed and lint-free cotton-free No. 1 and hybridizing it with dominant low-phenol cotton to obtain the F1 generation;

[0033] S2, self-pollinating the F1 generation until the next generation of lint-free and low-phenol traits do not separate, then stopping self-pollination and obtaining lint-free and low-phenol cotton;

[0034] S3, hybridizing lint-free low-phenol cotton with limited fruit-branch cotton to obtain the G1 generation;

[0035] S4. Self-pollinate the G1 generation to obtain the G2A generation with no lint, low phenol, and limited fruit branches and the G2B generation with no lint, low phenol, and unlimited fruit branches. Self-pollinate the G2A generation multiple times continuously with no lint, low phenol, and limited fruit branches as the target traits until stable cotton with no lint, low phenol, and limited fruit branches is obtained.

[0036] In the present invention, SGK321 cotton is first used to cultivate the light-seed and lint-free cotton No. 1, and then No. 1 cotton is hybridized with dominant low-phenol cotton MBI6055 to obtain the F1 generation;

[0037] The F1 generation now has the trait of down and low phenol, and continues to self-pollinate, and the F2 generation has trait separation, producing the F2A generation with down and low phenol, the F2B generation without down and low phenol, the F2C generation with down and normal phenol, and the F2D generation without down and normal phenol. The F2B generation without down and low phenol is selected for continuous self-pollination for 5 generations to obtain the F7 generation, at which time the down and low phenol traits no longer separate, and the down and low phenol cotton is obtained;

[0038] Then, the lint-free low-phenol cotton was crossed with the limited-fruit-branch cotton 1225 to obtain the G1 generation;

[0039] G1 represents lint-free, low-phenol, and unlimited fruit branches. The G1 generation is self-pollinated to obtain the G2 generation, producing the G2A generation and the G2B generation of lint-free, low-phenol, and unlimited fruit branches. The F2 generation is self-pollinated for 8 consecutive generations with lint-free, low-phenol, and limited fruit branches as the target traits to obtain stable lint-free, low-phenol, and limited fruit branches cotton.

[0040] Through the above hybridization process, the lint-free, low-phenol and limited fruit branch traits of cotton can be stabilized.

[0041] Planting SGK321 cotton in step S101 includes the following steps:

[0042] A. Building a breeding greenhouse, wherein the top and the periphery of the breeding greenhouse are covered with black sunshade cloth to block ultraviolet rays, and a light that does not generate ultraviolet rays is arranged in the breeding greenhouse;

[0043] B. Soak SGK321 cotton seeds in the catalyst for 30-60 minutes, dry them in the sun and sow them in the breeding greenhouse;

[0044] C. During the germination period, the temperature of the breeding greenhouse is maintained at 22-28°C, the soil humidity is 65-75%, and the air humidity is 70-80%;

[0045] D. Seedling stage, during which the temperature of the breeding greenhouse is maintained at 28-30℃, the soil humidity is 45-55%, and the air humidity is 80-90%;

[0046] E. Bud stage, during which the temperature of the breeding greenhouse is maintained at 30-35°C, the soil moisture is 45-55%, and the air humidity is 80-90%;

[0047] F. Flowering and boll forming period, during which the temperature of the breeding greenhouse is maintained at 30-32°C, the soil moisture is 45-55%, and the air humidity is 80-90%;

[0048] G. During the boll opening period, the temperature in the breeding greenhouse is maintained at 35-38°C, the soil moisture is 45-55%, and the air humidity is 70-80%.

[0049] The environmental variables in the cotton planting process are controlled to increase the probability of lint-free mutation of SGK321 cotton. First, one of the functions of short lint is to block part of the ultraviolet rays. Therefore, the present invention uses a sunshade cloth to reduce the ultraviolet radiation to which the cotton is exposed, and uses a light lamp without ultraviolet rays to make up for the daily lighting time required for the cotton. By reducing the demand of cotton for short lint, the probability of cotton mutating from lint-containing to lint-free is increased.

[0050] Secondly, one of the other functions of short lint is to promote plant transpiration by increasing the plant surface area. Therefore, this step controls environmental variables to keep the cotton in a high temperature and relatively water-deficient state during its growth process, so that the cotton itself needs to reduce transpiration, that is, the plant needs to inhibit the formation of short lint to increase the probability of cotton mutating from lint to no lint.

[0051] The preparation method of the catalyst is as follows: 75-85 mg of gibberellin, 80-100 μl of brassinolide, and 10-20 μmol of flavonoids are added to each liter of water, and the catalyst is obtained after being stirred evenly. The catalyst can not only promote the growth of cotton seeds to improve the emergence rate, but also add a flavonoid solution to the catalyst, which can increase the total amount of AM fungal hyphae in the soil and increase the host's absorption of nutrient elements in the soil.

[0052] The soil in the breeding greenhouse is applied with basal fertilizer, which includes 2.8-3kg / mu of nitrogen fertilizer, 5-6.5kg / mu of phosphorus fertilizer, and 2.8-3kg / mu of potassium fertilizer. Since the planting method of SGK321 cotton in the present invention is mainly to cultivate the mutant No Cotton 1, the temperature and soil moisture during the growth of cotton are relatively abnormal. In order to ensure the smooth growth of cotton, the amount of basal fertilizer applied in the soil needs to be slightly larger than the amount of basal fertilizer applied during ordinary cotton planting.

[0053] 2. Performance Test

[0054] Prepare a test field, divide the test field into 12 blocks and mark them as test groups 1-6 and control groups 1-6, transfer the soil of the test groups 1-6 to the breeding greenhouse using a planting container, plant SGK321 cotton in the test groups 1-6 according to the planting parameter range of the present invention, and self-pollinate the planted SGK321 cotton for 3 generations continuously, and place it in a breeding greenhouse with low ultraviolet light during the planting period, and the planting parameters of the test groups 1-6 are the same; the control groups 1-6 are planted in the test field according to the management parameters suitable for cotton in common knowledge, and the planting parameters of the control groups 1-6 are the same. The specific management parameters of the test groups 1-6 and the control groups 1-6 during the planting period are shown in Table 1, and the number of plants with velvet-free mutants in the test groups 1-6 and the control groups 1-6 during the planting period is recorded. Whenever the velvet-free mutant No Cotton 1 appears, it is transferred away to prevent it from contaminating other sample cottons. The specific mutation situation is shown in Table 2.

[0055] Table 1

[0056]

[0057]

[0058] Table 2

[0059]

[0060] It can be seen from Tables 1-2 that the present invention increases the probability of lint-free directional mutation of SGK321 cotton by an order of magnitude by controlling environmental variables during cotton planting, thereby reducing the probability of no mutants appearing after years of cultivation and shortening the breeding cycle of new cotton varieties.

Claims

1. A method for breeding lint-free, low-phenol, limited-fruit-branch cotton, characterized in that: The following steps are involved: S1, preparing the bare-seed and lint-free cotton-free No. 1 and hybridizing it with dominant low-phenol cotton to obtain the F1 generation; S2, self-pollinating the F1 generation until the next generation of lint-free and low-phenol traits do not separate, then stopping self-pollination and obtaining lint-free and low-phenol cotton; S3, hybridizing lint-free low-phenol cotton with limited fruit-branch cotton to obtain the G1 generation; S4. Self-pollinate the G1 generation to obtain the G2A generation with no lint, low phenol, and limited fruit branches and the G2B generation with no lint, low phenol, and unlimited fruit branches. Self-pollinate the G2A generation multiple times continuously with no lint, low phenol, and limited fruit branches as the target traits until stable cotton with no lint, low phenol, and limited fruit branches is obtained.

2. The breeding method of a lint-free, low-phenol, limited-fruit-branch cotton according to claim 1, characterized in that: The method for obtaining the No. 1 cotton-free product comprises the following steps: S101, planting SGK321 cotton until a mutant with bare seeds and no lint is selected; S102. Self-pollinate the seedless and lint-free mutant for at least six generations to obtain No. 1 Cotton-Free, which has a stably inherited lint-free trait.

3. The breeding method of a lint-free, low-phenol, limited-fruit-branch cotton according to claim 2, characterized in that: Planting SGK321 cotton in step S101 includes the following steps: A. Building a breeding greenhouse, wherein the top and the periphery of the breeding greenhouse are covered with black sunshade cloth to block ultraviolet rays, and a light that does not generate ultraviolet rays is arranged in the breeding greenhouse; B. Soak SGK321 cotton seeds in the catalyst for 30-60 minutes, dry them in the sun and sow them in the breeding greenhouse; C. During the germination period, the temperature of the breeding greenhouse is maintained at 22-28°C, the soil humidity is 65-75%, and the air humidity is 70-80%; D. Seedling stage, during which the temperature of the breeding greenhouse is maintained at 28-30℃, the soil humidity is 45-55%, and the air humidity is 80-90%; E. Bud stage, during which the temperature of the breeding greenhouse is maintained at 30-35°C, the soil moisture is 45-55%, and the air humidity is 80-90%; F. Flowering and boll forming period, during which the temperature of the breeding greenhouse is maintained at 30-32°C, the soil moisture is 45-55%, and the air humidity is 80-90%; G. During the boll opening period, the temperature in the breeding greenhouse is maintained at 35-38°C, the soil moisture is 45-55%, and the air humidity is 70-80%.

4. The breeding method of a lint-free, low-phenol, limited-fruit-branch cotton according to claim 3, characterized in that: The preparation method of the catalyst is as follows: 75-85 mg of gibberellin, 80-100 μl of brassinolide and 10-20 μmol of flavonoids are added into each liter of water, and the mixture is stirred evenly to obtain the catalyst.

5. The method for breeding lint-free, low-phenolic, limited-fruit-branch cotton according to claim 3, characterized in that: Base fertilizer is applied to the soil in the breeding greenhouse, and the base fertilizer includes 2.8-3kg / mu of nitrogen fertilizer, 5-6.5kg / mu of phosphorus fertilizer, and 2.8-3kg / mu of potassium fertilizer.

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