Fertility Changing And Restoration Of Photo-thermo-sensitive Genic Male Sterile Wheat

Fertility changing of photo-thermo-sensitive genie male sterile(PTGMS) line is one of the cores of two-line hybrid wheat research, and the issue of the restoration is concerned increasingly by the breeders. The objective of this study is to perceive the fertility changing and the restoration of PTGMS wheat.The plant materials in this study were PTGMS wheat line BS20 and BS210 which were developed by Hybrid Research Center, BAAFS. The study of fertility changing was carried out in photo-thermo controlled growth chambers combined with photoperiod control in the field. The results showed that the stage of photo-sensitivity and thermo-sensitivity was coincident from anther chamber formation to mononucleate. BS20 and BS210 showed sterility under the conditions of short day length and low temperature. However, their reaction mechanism and genetic types were different. Fertility changing of BS20 was induced by photoperiod and temperature, but thermo-sensitivity played a leading role. Lower(8℃) or higher(16℃) temperature can cover the effect of photoperiod. At the day average temperature of 12℃, the fertility of BS20 increased and the critical temperature decreased with longer day-length. BS210 was thermo-sensitive genie male sterile line, and was not influenced by photoperiod. The critical temperature of BS210 was 12℃. Anther development suggested that the male fertility abortion of BS20 showed two phenomenons. One exhibited abnormal chromosome in tetrad stage of meiosis. The other showed the farina accumulation existing obstacle in the prophase of pollen maturation.Wheat varieties or lines selected from different regions of China and CIMMYT were used as the restoier lines, and the BS20 and BS210 were used as the sterile lines. The fertility performance of F, hybrids was analysed. The results revealed that PTGMS lines had the difficulty of restoration. Most varieties or lines can only partially restore the fertility. Only few can restore the fertility completely. BS20 was more difficultly restored than BS210. However, weak photo-sensitive CIMMYT varieties or lines can easily restore the fertility of BS20.