Fertility of Four Environment-sensitive Genic Male-sterile Indica Rices in Wuchang

Four practical photo-/ thermo-sensitive genic male-sterile lines,YW-2S, Guangzhan 63S,1103S, Pei’ai 64S, were sequentially seeded with 10d interval under natural conditions at Wuchang in 2003. The results of investigations on fertility expression showed that both photoperiod and temperature were important factors controlling fertility alteration of P(T)GMS lines, To a certain extent, their critical temperature inducing male sterility would be lower under longer day-length and higher under longer day-length and will be higher under shorter day-length. Their fertility expression and characteristics of fertility alteration varied from line to line. According to Correlation coefficients between daily mean temperature and self-sterility, the sensitive stage to temperature for fertility alteration of YW-2S was 21～13d before heading. The sensitive stage was 21～14d before heading in 1103S, 21～13d in Pei’ai 64S and 18～9d in Guangzhan 63S.