Modified single-cross for hybrid rice breeding

摘要

L129A is a cytoplasmic male sterile (CMS) line of the WA type. L129-4-8, L129-4-9, L129-6-2, and L129-12-7 are sister lines of L129B with partial maintainers for male sterility. It was observed that high outcrossing was associated with low male sterility in the population of V20A/6*L129-12-7 BC6F1. When L129A was crossed with the four sister lines of L129B, it produced male sterile F1s with much improved outcrossing habit. The results showed that the F1 of A/partial maintainer induced less negative impact of male sterility on outcrossing. In this paper, a modified single-cross approach to develop hybrid rice was suggested.A method of using regular CMS A, B, and R lines and a partial maintainer line(B′) was proposed to increase the seed yield of seed production of hybrid rice and make CMS lines with poor outcrossing useful. The breeding method for B′was also studied.