Breeding method of big-stigma two-line rice sterile line

Abstract

The invention discloses a breeding method of a big-stigma two-line rice sterile line, belonging to the technical field of rice heterosis utilization. The method comprises the following steps: sprouting seeds of the two-line rice sterile line till white sprouts come out, then radiating the seeds with 60 Co-gamma rays of which the dosage is 50-80Gy so as to obtain big-stigma trait mutants; observing the mutants on the aspects of economical trait, yield trait, flowering and pollen spreading trait, and finally breeding the big-stigma two-line rice sterile line, wherein the glumous flower stigma of the bred big-stigma two-line rice sterile line is twice or three times as large as that of a common sterile line. The physical radiation-induced mutation method for breeding the big-stigma two-line rice sterile line needs short time and can achieve high breeding efficiency, the whole breeding process only needs 3-4 planting generations in 2 years. The breeding method has the advantages that big-stigma trait mutation frequency is 0.03-0.04%, the stigma exposure rate is higher than 90%, and the outcrossing rate and seed production yield of the two-line rice sterile line can be improved remarkably.

Description

technical field [0001] The invention specifically relates to a method for breeding a large stigma two-line sterile line of rice, and belongs to the technical field of rice heterosis utilization. Background technique [0002] Hybrid rice seed production is to use the pollen of the male parent to scatter on the stigma (pistil) of the sterile flower to make it fertilized and firm. The structure of the rice flower organ is suitable for self-fertilization but not for outcrossing. Pollen from the male parent is more difficult to scatter to the stigma of the sterile line, which is the limiting factor for improving the yield of hybrid rice seed production. If the stigma of the sterile line is exposed outside the florets (exposed stigma), it is beneficial to pollination of the male parent, while the stigma of the male sterile line with large stigma has a high rate of stigma exposure, and the seed production yield is higher than that of the ordinary small stigma CMS. However, so far,...

AI Technical Summary

Problems solved by technology

However, so far, there are few studies on the large stigma CMS line of rice, especially the breeding of two-line CMS line of rice large stigma by means of radiation mutagenesis, which has not been reported so far.

If the large stigma trait is introduced into the two-line CMS line by traditional hybrid backcrossing method, not only the workload of selection and breeding will be large, but the breeding period will be long, and the comprehensive traits of the bred CMS line will be unsatisfactory.

The entire breeding process generally takes 5-6 years, which is time-consuming and labor-intensive, and the benefits are low