Seed production techniques of Cotton male sterile Lines

The technology of cotton male sterile line seed production uses insect-assisted pollination male sterile line hybrid seed production method, which overcomes the shortcomings of artificial de-pollination hybrid seed production method, which is widely used at present, such as time-consuming and labor-consuming, high intensity of work, complex management of seed production field and high cost of seed production. The labor consumption can be reduced by more than 50%, and the purity of hybrid seeds can be further improved. It is the most ideal way to produce cotton hybrid seeds.

Cotton male sterile line seed production technology is to cultivate transgenic insect-resistant double recessive male sterile lines with recessive low-phenol markers and carry out insect-assisted pollination seed production, in order to solve the current cotton hybrid seed production technology of time-consuming and labor-intensive, and lead to a series of problems such as false hybrids and so on.

This technique uses the hybrid seed production method of insect-assisted pollination male sterile lines to overcome the shortcomings of the widely used cotton hybrid seed production method-artificial de-pollination hybrid seed production method, such as time-consuming, high intensity of work, complex management of seed production and high cost of seed production. The amount of labor can be reduced by more than 50%, and the purity of hybrid seeds can be further improved. It is the most ideal way to produce cotton hybrid seeds.

Brief technology

Based on the transgenic insect-resistant double recessive male sterile line Zhongkang A, a transgenic insect-resistant double recessive male sterile line with low phenol marker was cultivated for insect-assisted pollination breeding, which not only simplifies the seed production procedure and reduces the breeding workload, but also distinguishes the true and false hybrids by measuring the presence of pigment glands on the seedling bed or cutting seed kernels, and those with pigment glands are true hybrids, otherwise they are false hybrids. As a result, the economic loss is avoided and can be used for large-scale production of hybrid seeds.

After sexual hybridization, the recessive glandless gene was transferred into Zhongkang A, and in the fertility separation population of its offspring, plant-to-plant hybridization (sterility × fertility) was conducted to investigate the proportion of fertility segregation and the existence of glands in its offsprings. combined with the observation of agronomic characters, after many years of directional selection, the male sterile line materials with insect resistance, low phenol and stable male sterile plant rate were selected as follows:

1. Transfer of recessive low-phenol semi-maintainer lines. The recessive low-phenol insect-resistant cotton line was used as the male parent and the medium-resistant An as the female parent. F1 was added to Hainan Island, and the low-phenol fertile plant was selected from the F2 generation as the male parent, and the isolated male sterile plant was hybridized with the isolated male sterile plant. Plant-to-plant harvest, plant in the second year, investigate fertility and retain the plant row with a sterile plant rate of 50%.

two。 Purification of low phenol double recessive genic male sterile line. The glands of the plants with a sterile plant rate of 50% were observed, and the fertile plants with low phenols and the sterile plants with low phenols were selected for plant-to-plant hybridization, and the hybrids and test hybrids were collected according to the plant. Using Hainan Island winter plus generation, after plant-to-plant hybridization and test crossing for 3 consecutive years, a stable insect-resistant and low-phenol double recessive genic male sterile line was bred. The male sterile line has excellent comprehensive agronomic characters and high resistance to cotton bollworm. Plant tower shape, moderate leaves, strong boll setting, thin boll shell, smooth boll opening, 100% sterility, stable and thorough sterility.

Application prospect

1. Compared with the existing artificial de-pollination hybrid seed production method, the invention can greatly reduce the labor intensity in the field of seed production, reduce the workload, improve the work efficiency of seed production, and thus greatly reduce the cost of seed production.

two。 With the male sterile line of the invention as the female parent, it is easy to distinguish between true and false hybrids, and can be easily pulled out on the seedbed, and the field seed production of the male sterile line can be produced with the aid of insect pollination in a large area and on a large scale.

3. The male sterile line of the invention has a wide range of restoration sources, and general upland cotton varieties (lines) can be used as their restorer lines, with obvious heterosis, a competitive advantage of 115% Mel 136%, and good insect resistance.