A method for breeding a high tannin content cytoplasmic male sterile line of sorghum

Abstract

The application provides a breeding method of a high-tannin-content sorghum cytoplasmic male sterile line, which comprises the following steps: taking a known cytoplasmic male sterile maintainer line as a female parent, and crossing it with a conventional high-tannin-content sorghum variety as a male parent to obtain F1 generation seeds; selfing the F1 generation seeds to obtain F2 generation seeds; screening the F2 generation seeds after planting to obtain F3 generation seeds; harvesting and screening the F3 generation seeds to obtain an F4 generation line; selfing the F4 generation line after planting to obtain an F5 generation line; crossing the F4 generation line with a known cytoplasmic male sterile line to obtain a test cross 1 generation; backcrossing the F5 generation line with the test cross 1 generation to obtain a backcross 1 generation; backcrossing to a backcross 6 generation; and screening a high-tannin-content sorghum cytoplasmic male sterile line which is consistent with the F10 generation line in agronomic characters, stable in sterility and high in tannin content. The high-tannin-content sorghum cytoplasmic male sterile line bred by the application can effectively prevent birds from pecking during seed production, and the high-tannin-content sterile line is crossed with a restorer line, which is beneficial to increasing the tannin content of a hybrid combination and increasing the sorghum wine flavor.

Description

Technical Field

[0001] This invention belongs to the field of genetic breeding technology, specifically relating to a method for breeding a cytoplasmic male sterile line of sorghum with high tannin content. Background Technology

[0002] Sorghum [Sorghum bicolor (L.) Moench] is one of China's important cereal crops. It possesses multiple resistances, including drought tolerance, flood tolerance, poor soil tolerance, and salt and alkali tolerance, and can be planted in plains, hills, and saline-alkali lands. It boasts high biological and economic yields. Sorghum is primarily utilized through a three-line hybridization system to exploit heterosis. Currently, the tannin content of sorghum sterile lines is generally low, leading to significant bird pecking during seed production, which severely impacts seed yield. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for breeding a sorghum cytoplasmic male sterile line with high tannin content, which addresses the shortcomings of the prior art. The method of breeding a sorghum cytoplasmic male sterile line with high tannin content and then hybridizing it with a restorer line is beneficial to increasing the tannin content of the hybrid combination and enhancing the flavor of sorghum wine.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for breeding cytoplasmic male sterile lines of sorghum with high tannin content, the method being as follows:

[0005] S1. Using a known cytoplasmic male sterility maintainer line as the female parent, and crossing it with a conventional sorghum variety with high tannin content as the male parent, F1 generation seeds are obtained; the tannin content of the cytoplasmic male sterility maintainer line is lower than the tannin content of the conventional sorghum variety with high tannin content.

[0006] S2. The F1 generation seeds obtained from S1 are bagged, self-pollinated, and harvested to obtain the F2 generation seeds.

[0007] S3. Select sorghum plants with excellent agronomic traits from the F2 generation seeds obtained from S2 that are astringent when chewed during the milk stage, have not been pecked by birds during the mature stage, and are harvested to obtain F3 generation seeds and establish a lineage.

[0008] S4. Plant the F3 generation seeds obtained in S3, select sorghum plants that are astringent to chew during the milk stage, have not been pecked by birds during the mature stage, and have excellent agronomic traits, and harvest F4 generation seeds from the lines established by the F3 generation seeds as described in S3 to obtain F4 generation lines. Measure the tannin content of each F4 generation line, and retain seeds with a tannin content ≥1.3% from the F4 generation lines to obtain F4 generation varieties.

[0009] S5. When the sorghum is heading and flowering, the F4 generation line obtained in S4 is planted, and the known sorghum cytoplasmic male sterile line described in S1 is used as the female parent. Individual plants with excellent agronomic traits are selected from the F4 generation line for paired testcrosses. Individual plants with excellent agronomic traits in the F4 generation line are testcrossed with the known sorghum cytoplasmic male sterile line to obtain the first generation of testcrosses. Individual plants with excellent agronomic traits in the F4 generation line are self-pollinated to obtain the F5 generation line. Seeds with a tannin content ≥1.3% are retained from the F5 generation line to obtain the F5 generation line.

[0010] S6. Plant the F5 generation line obtained in S5 and the testcross generation 1 obtained in S5 in pairs. When the sorghum is heading and flowering, test the sterility of the testcross generation 1. Backcross the testcross generation 1 with the individual plants of the F5 generation line that have excellent agronomic traits and can maintain the sterility of the testcross generation 1. Then, selfcross the individual plants of the F5 generation line that have excellent agronomic traits to obtain the F6 generation line. Retain the seeds with tannin content ≥1.3% from the F6 generation line to obtain the F6 generation line.

[0011] S7. Backcross the F6 generation line obtained in S6 with the backcross 1 generation obtained in S6 to obtain the backcross 2 generation. Self-pollinate the F6 generation line with excellent agronomic traits to obtain the F7 generation line. Retain seeds with tannin content ≥1.3% from the F7 generation line to obtain the F7 generation line.

[0012] S8. Backcross the F7 generation line with the agronomically superior individual plants obtained in S7 with the backcross 2 generation obtained in S7 to obtain the backcross 3 generation. Self-pollinate the F7 generation line with the agronomically superior individual plants to obtain the F8 generation line.

[0013] S9. Backcross the F8 generation line obtained in S8 with the backcross 3 generation obtained in S8 to obtain the backcross 4 generation. Self-pollinate the F8 generation line with the agronomically superior individual plants to obtain the F9 generation line.

[0014] S10. Backcross the F9 generation line obtained in S9 with the backcross 4 generation obtained in S9 to obtain the backcross 5 generation. Self-pollinate the F9 generation line with the agronomically excellent individual plants to obtain the F10 generation line.

[0015] S11. Backcross the F10 generation lines obtained in S10 with the backcrossed 5th generation obtained in S10 to obtain the 6th generation backcross. Select sorghum cytoplasmic male sterile lines with consistent agronomic traits, stable sterility and high tannin content, which are the high tannin content sorghum cytoplasmic male sterile lines.

[0016] Preferably, the tannin content of the known cytoplasmic male sterility maintainer line in S1 is ≤0.05%; the tannin content of the conventional sorghum variety with high tannin content is 1.5% to 1.8%.

[0017] Preferably, the known cytoplasmic male sterility maintainer line is the A1 type cytoplasmic male sterility maintainer line, and the conventional sorghum variety with high tannin content is Nuoliang No. 1 or Hongmaoliang No. 6 sorghum.

[0018] Preferably, the number of F2 seeds planted in S3 is not less than 2000.

[0019] Preferably, the agronomic traits mentioned in S3-S11 are plant growth, plant height, number of branches and stalks, and fruit setting rate.

[0020] Preferably, the tannin content of the sorghum cytoplasmic male sterile line with high tannin content described in S11 is 1.5% to 1.7%.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] This invention yields a high-tannin cytoplasmic male-sterile sorghum line with excellent traits. The high tannin content can prevent birds from pecking at the sorghum during seed production, thereby increasing seed yield. Crossbreeding the high-tannin cytoplasmic male-sterile sorghum line with the restorer line is beneficial for increasing the tannin content of the hybrid combination and enhancing the flavor of sorghum for brewing.

[0023] The present invention will be further described in detail below with reference to the embodiments. Detailed Implementation

[0024] Example 1

[0025] The method for breeding high-tannin sorghum cytoplasmic male sterile lines in this embodiment is as follows:

[0026] S1. Using the known cytoplasmic male sterility maintainer line 54B as the female parent, a cross is conducted with a conventional sorghum variety with high tannin content as the male parent to obtain F1 generation seeds; the tannin content of the cytoplasmic male sterility maintainer line is lower than that of the conventional sorghum variety with high tannin content; the tannin content of the known cytoplasmic male sterility maintainer line is 0.05%; the tannin content of the conventional sorghum variety with high tannin content is 1.5%; the known cytoplasmic male sterility maintainer line is an A1 type cytoplasmic male sterility maintainer line, and the conventional sorghum variety with high tannin content is Nuoliang No. 1;

[0027] S2. The F1 generation seeds obtained from S1 are bagged, self-pollinated, and harvested to obtain the F2 generation seeds.

[0028] S3. Select individual sorghum plants with excellent agronomic traits from the F2 generation seeds obtained in S2 that are astringent to chew during the milk stage, have not been pecked by birds during the mature stage, and have good agronomic traits to harvest, and obtain F3 generation seeds to establish a lineage; the number of F2 seed plants planted shall not be less than 2000.

[0029] S4. Plant the F3 generation seeds obtained in S3, select sorghum plants that are astringent to chew during the milk stage, have not been pecked by birds during the mature stage, and have excellent agronomic traits, and harvest F4 generation seeds from the lines established by the F3 generation seeds as described in S3 to obtain F4 generation lines. Measure the tannin content of each F4 generation line, and retain seeds with a tannin content ≥1.3% from the F4 generation lines to obtain F4 generation varieties.

[0030] S5. When the sorghum is heading and flowering, the F4 generation line obtained in S4 is planted, and the known sorghum cytoplasmic male sterile line described in S1 is used as the female parent. Individual plants with excellent agronomic traits are selected from the F4 generation line for paired testcrosses. Individual plants with excellent agronomic traits in the F4 generation line are testcrossed with the known sorghum cytoplasmic male sterile line to obtain the first generation of testcrosses. Individual plants with excellent agronomic traits in the F4 generation line are self-pollinated to obtain the F5 generation line. Seeds with a tannin content ≥1.3% are retained from the F5 generation line to obtain the F5 generation line.

[0031] S6. Plant the F5 generation line obtained in S5 and the testcross generation 1 obtained in S5 in pairs. When the sorghum is heading and flowering, test the sterility of the testcross generation 1. Backcross the testcross generation 1 with the individual plants of the F5 generation line that have excellent agronomic traits and can maintain the sterility of the testcross generation 1. Then, selfcross the individual plants of the F5 generation line that have excellent agronomic traits to obtain the F6 generation line. Retain the seeds with tannin content ≥1.3% from the F6 generation line to obtain the F6 generation line.

[0032] S7. Backcross the F6 generation line with the agronomically superior individual plants obtained in S6 with the backcross generation 1 obtained in S6 to obtain backcross generation 2. Self-pollinate the F6 generation line with the agronomically superior individual plants to obtain F7 generation line. Retain seeds with tannin content ≥1.3% from the F7 generation line to obtain the F7 generation line.

[0033] S8. Backcross the F7 generation line with the agronomically superior individual plants obtained in S7 with the backcross 2 generation obtained in S7 to obtain the backcross 3 generation. Self-pollinate the F7 generation line with the agronomically superior individual plants to obtain the F8 generation line.

[0034] S9. Backcross the F8 generation line obtained in S8 with the backcross 3 generation obtained in S8 to obtain the backcross 4 generation. Self-pollinate the F8 generation line with the agronomically superior individual plants to obtain the F9 generation line.

[0035] S10. Backcross the F9 generation line obtained in S9 with the backcross 4 generation obtained in S9 to obtain the backcross 5 generation. Self-pollinate the F9 generation line with the agronomically superior individual plants to obtain the F10 generation line.

[0036] S11. The superior agronomical individual plants from the F10 generation obtained in S10 are backcrossed with the 5th generation backcross obtained in S10 to obtain the 6th generation backcross. The sorghum cytoplasmic male sterile line with the same agronomical traits as the F10 generation line, stable sterility and high tannin content is selected, which is the high tannin content sorghum cytoplasmic male sterile line; the tannin content of the high tannin content sorghum cytoplasmic male sterile line is 1.5%;

[0037] The agronomic traits described in S3-S11 are plant growth, plant height, number of branches and stalks, and fruit setting rate.

[0038] Example 2

[0039] The method for breeding high-tannin sorghum cytoplasmic male sterile lines in this embodiment is as follows:

[0040] S1. Using the known cytoplasmic male sterility maintainer line 407B as the female parent, a cross is conducted with a conventional sorghum variety with high tannin content as the male parent to obtain F1 generation seeds; the tannin content of the cytoplasmic male sterility maintainer line is lower than that of the conventional sorghum variety with high tannin content; the tannin content of the known cytoplasmic male sterility maintainer line is 0.03%; the tannin content of the conventional sorghum variety with high tannin content is 1.8%; the known cytoplasmic male sterility maintainer line is an A1 type cytoplasmic male sterility maintainer line, and the conventional sorghum variety with high tannin content is Hongmaoliang No. 6 sorghum;

[0041] S2. The F1 generation seeds obtained from S1 are bagged, self-pollinated, and harvested to obtain the F2 generation seeds.

[0042] S3. Select individual sorghum plants with excellent agronomic traits from the F2 generation seeds obtained in S2 that are astringent to chew during the milk stage, have not been pecked by birds during the mature stage, and have good agronomic traits to harvest, and obtain F3 generation seeds to establish a lineage; the number of F2 seed plants planted shall not be less than 2000.

[0043] S4. Plant the F3 generation seeds obtained in S3, select sorghum plants that are astringent to chew during the milk stage, have not been pecked by birds during the mature stage, and have excellent agronomic traits, and harvest F4 generation seeds from the lines established by the F3 generation seeds as described in S3 to obtain F4 generation lines. Measure the tannin content of each F4 generation line, and retain seeds with a tannin content ≥1.3% from the F4 generation lines to obtain F4 generation varieties.

[0044] S5. When the sorghum is heading and flowering, the F4 generation line obtained in S4 is planted, and the known sorghum cytoplasmic male sterile line described in S1 is used as the female parent. Individual plants with excellent agronomic traits are selected from the F4 generation line for paired testcrosses. Individual plants with excellent agronomic traits in the F4 generation line are testcrossed with the known sorghum cytoplasmic male sterile line to obtain the first generation of testcrosses. Individual plants with excellent agronomic traits in the F4 generation line are self-pollinated to obtain the F5 generation line. Seeds with a tannin content ≥1.3% are retained from the F5 generation line to obtain the F5 generation line.

[0045] S6. Plant the F5 generation line obtained in S5 and the testcross generation 1 obtained in S5 in pairs. When the sorghum is heading and flowering, test the sterility of the testcross generation 1. Backcross the testcross generation 1 with the individual plants of the F5 generation line that have excellent agronomic traits and can maintain the sterility of the testcross generation 1. Then, selfcross the individual plants of the F5 generation line that have excellent agronomic traits to obtain the F6 generation line. Retain the seeds with tannin content ≥1.3% from the F6 generation line to obtain the F6 generation line.

[0046] S7. Backcross the F6 generation line with the agronomically superior individual plants obtained in S6 with the backcross generation 1 obtained in S6 to obtain backcross generation 2. Self-pollinate the F6 generation line with the agronomically superior individual plants to obtain F7 generation line. Retain seeds with tannin content ≥1.3% from the F7 generation line to obtain the F7 generation line.

[0047] S8. Backcross the F7 generation line with the agronomically superior individual plants obtained in S7 with the backcross 2 generation obtained in S7 to obtain the backcross 3 generation. Self-pollinate the F7 generation line with the agronomically superior individual plants to obtain the F8 generation line.

[0048] S9. Backcross the F8 generation line obtained in S8 with the backcross 3 generation obtained in S8 to obtain the backcross 4 generation. Self-pollinate the F8 generation line with the agronomically superior individual plants to obtain the F9 generation line.

[0049] S10. Backcross the F9 generation line obtained in S9 with the backcross 4 generation obtained in S9 to obtain the backcross 5 generation. Self-pollinate the F9 generation line with the agronomically superior individual plants to obtain the F10 generation line.

[0050] S11. The superior agronomical individual plants from the F10 generation obtained in S10 are backcrossed with the 5th generation backcross obtained in S10 to obtain the 6th generation backcross. The sorghum cytoplasmic male sterile line with the same agronomical traits as the F10 generation line, stable sterility and high tannin content is selected, which is the high tannin content sorghum cytoplasmic male sterile line; the tannin content of the high tannin content sorghum cytoplasmic male sterile line is 1.7%;

[0051] The agronomic traits described in S3-S11 are plant growth, plant height, number of branches and stalks, and fruit setting rate.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. A method for breeding a cytoplasmic male-sterile sorghum line with high tannin content, characterized in that, The method is as follows: S1. Using a known cytoplasmic male sterility maintainer line as the female parent, cross it with a conventional sorghum variety with high tannin content as the male parent to obtain F1 generation seeds; the tannin content of the cytoplasmic male sterility maintainer line is lower than that of the conventional sorghum variety with high tannin content; the known cytoplasmic male sterility maintainer line is cytoplasmic male sterility maintainer line 407B, and the conventional sorghum variety with high tannin content is Nuoliang No. 1 or Hongmaoliang No. 6 sorghum; the tannin content of the known cytoplasmic male sterility maintainer line is ≤0.05%; the tannin content of the conventional sorghum variety with high tannin content is 1.5% to 1.8%; S2. The F1 generation seeds obtained from S1 are bagged, self-pollinated, and harvested to obtain the F2 generation seeds. S3. Select sorghum plants with excellent agronomic traits from the F2 generation seeds obtained in S2 that are astringent to chew during the milk stage, have not been pecked by birds during the mature stage, and are harvested to obtain F3 generation seeds and establish a lineage; the agronomic traits are plant growth, plant height, number of branches and stalks and seed setting rate; the number of F2 generation seeds planted shall not be less than 2000 plants. S4. Plant the F3 generation seeds obtained in S3, select sorghum plants that are astringent to chew during the milk stage, have not been pecked by birds during the mature stage, and have excellent agronomic traits, and harvest F4 generation seeds from the lines established by the F3 generation seeds as described in S3 to obtain F4 generation lines. Measure the tannin content of each F4 generation line, and retain seeds with a tannin content ≥1.3% from the F4 generation lines to obtain F4 generation varieties. S5. When the sorghum is heading and flowering, the F4 generation line obtained in S4 is planted, and the known sorghum cytoplasmic male sterile line described in S1 is used as the female parent. Individual plants with excellent agronomic traits are selected from the F4 generation line for paired testcrosses. Individual plants with excellent agronomic traits in the F4 generation line are testcrossed with the known sorghum cytoplasmic male sterile line to obtain the first generation of testcrosses. Individual plants with excellent agronomic traits in the F4 generation line are self-pollinated to obtain the F5 generation line. Seeds with a tannin content ≥1.3% are retained from the F5 generation line to obtain the F5 generation line. S6. Plant the F5 generation line obtained in S5 and the testcross generation 1 obtained in S5 in pairs. When the sorghum is heading and flowering, test the sterility of the testcross generation 1. Backcross the testcross generation 1 with the individual plants of the F5 generation line that have excellent agronomic traits and can maintain the sterility of the testcross generation 1. Then, selfcross the individual plants of the F5 generation line that have excellent agronomic traits to obtain the F6 generation line. Retain the seeds with tannin content ≥1.3% from the F6 generation line to obtain the F6 generation line. S7. Backcross the F6 generation line with the agronomically superior individual plants obtained in S6 with the backcross generation 1 obtained in S6 to obtain backcross generation 2. Self-pollinate the F6 generation line with the agronomically superior individual plants to obtain F7 generation line. Retain seeds with tannin content ≥1.3% from the F7 generation line to obtain the F7 generation line. S8. Backcross the F7 generation line with the agronomically superior individual plants obtained in S7 with the backcross 2 generation obtained in S7 to obtain the backcross 3 generation. Self-pollinate the F7 generation line with the agronomically superior individual plants to obtain the F8 generation line. S9. Backcross the F8 generation line obtained in S8 with the backcross 3 generation obtained in S8 to obtain the backcross 4 generation. Self-pollinate the F8 generation line with the agronomically superior individual plants to obtain the F9 generation line. S10. Backcross the F9 generation line obtained in S9 with the backcross 4 generation obtained in S9 to obtain the backcross 5 generation. Self-pollinate the F9 generation line with the agronomically superior individual plants to obtain the F10 generation line. S11. The superior agronomical individual plants from the F10 generation obtained in S10 are backcrossed with the 5th generation backcross obtained in S10 to obtain the 6th generation backcross. The sorghum cytoplasmic male sterile line with the same agronomical traits as the F10 generation line, stable sterility and high tannin content is selected, which is the high tannin content sorghum cytoplasmic male sterile line; the tannin content of the high tannin content sorghum cytoplasmic male sterile line is 1.5% to 1.7%.