Breeding and Characteristics of Photoperiod Sensitive Genic Male Sterile Line Wan 2304S 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 Wan 2304S.[Methods] 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 Wan 2304S in japonica rice was bred through selection for 7 generations in 4 years.[Result] From Aug.12nh to 28th in 2009,Wan 2304S showed male sterility,its pollen abortive rate in microscopic examination was 99.54%-100.00%,its bagged seed setting rate was 0-0.07%.From Aug.31st to Sep.21st,it showed male fertility,its pollen abortive rate in microscopic examination was 79.94%-99.79% and its bagged seed setting rate was 0.56%-28.76%.From Aug.2nd to Sep.1st in 2010,Wan 2304S showed male sterility,its pollen abortive rate in microscopic examination was 99.53%-100.00%,its bagged seed setting rate was 0-0.36% and its steady sterile period was 31 d,from Sep.3rd to Sep.17th in 2010,it showed male fertility,its pollen abortive rate in microscopic examination was 96.38%-99.46% and its bagged seed setting rate was 0.57%-18.82%.Under long photo period,the critical temperature for inducing male sterility was lower than 24 ℃.The resistance of Wan 2304S 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 japonica combination.