Breeding of Photoperiod Sensitive Genic Male Sterile Line Wan2312S in Japonica Rice

[Objective] The purpose of the research was to introduce the breeding process,fertility performance,disease resistance and agronomic characters of photoperiod sensitive genic male sterile line Wan2312S.[Method] With photoperiod sensitive genic male sterile line 7001S in japonica rice as female parent,it was hybridized with Shuangjiu,the photoperiod sensitive genic male sterile line Wan2312S in japonica rice was bred through selection for 11 generations in 6 years.[Result] From Aug.1st to Aug.31st in 2007,Wan2312S showed male sterility,its pollen abortive rate in microscopic examination was 99.72%-100.00%,its bagged seed setting rate was 0~0.43% and its steady sterile period was 31 d;from Sep.3rd to Sep.14th,it showed male fertility,its pollen abortive rate in microscopic examination was 74.80%-99.47% and its bagged seed setting rate was 1.43%-9.54%.From Jul.31st to Sep.1st in 2008,Wan2312S showed male sterility,its pollen abortive rate in microscopic examination was 99.91%-100.00%,its bagged seed setting rate was 0-0.48% and its steady sterile period was 33 d;from Sep.3rd to Sep.21st,it showed male fertility,its pollen abortive rate in microscopic examination was 69.99%-99.91% and its bagged seed setting rate was 0.33%-42.75%.The resistance of Wan2312S planted in field to rice stripe disease was stronger.[Conclusion] The steady sterile period of this sterile line was longer than 30 d,so it was suitable for matching middle japonic combination.