Abstract: Fertility alteration characteristics and flowering habits of PGMR were studied under the local natural condition in Gongzhuling (43°21′N) and problem of using PGMR for hybrid rice breeding in the cold region were discussed. The critical photoperiod of fertility alteration of PGMR was 14.5-14.0 hours, but the local photoperiod could only meet the requirement of sterility of PGMR in the cold region over 38°N. Daily flowering time of PGMR was about 1 hours later and more dispersive than these of normal variety. It was low in the crossed pollination rate between PGMR and normal variety. Sterility of existing PGMR was unstable in the cold region. Fertility of PGMR was affected by temperature during differentiation stage of floret primodium.

Key words: Fertility alteration, Hybrid japonica rice, Photoperiod-sensitive genic male-sterile rice, The cold rice region

关键词: 杂交水稻, 育性转换, 开花, 寒冷稻区, 光温敏核不育水稻