温敏型雄不育小麦C49S育性转换与温度的关系

THE RELATIONSHIP BETWEEN FERTILITY TRANSFORMATION AND TEMPERATURE IN THERMO-SENSITIVE MALE-STERILE WHEAT“C49S”(TRITCUM EASTIVUML)

通过分期播种，孕穗、抽穗期和结实率的调查，研究了温敏型雄不育小麦Ｃ４９Ｓ的育性与播期及温度的关系。结果表明，随着播种期推迟，不育率由９７．１４％降到３５．９４％，不育率与减数分裂期──孕穗前５日的平均最低温度（Ｔ＿(ｍｉｎ)）和平均温度（Ｔ）呈极显著负相关，γＴｍｉｎ＝－０．８１８，γＴ＝－０．６２２。Ｃ４９Ｓ育性转换主要受制于Ｔ＿(ｍｉｎ)，Ｔ起一定调节作用。在Ｔ＿(ｍｉｎ)＜７．７℃，Ｔ＜１０℃条件下，Ｃ４９Ｓ高度不育，结实率在４％以下；在Ｔｍｉｎ＞１１．５℃条件下，Ｃ４９Ｓ育性恢复正常，结实率在５０％以上。

C49S,a thermo-sensitive male-sterile wheat, was sown on different dates andits booting date,heading date and fruiting rate were recorded.With the deferring of sow-ing date,the sterility rate reduced progressively from 97.14 percent to 35.94 percent.Asignificant negative relationship was observed btween the sterility rate, on the one hand,and mean minimum temperatureand mean temperature(T)during the reductionaldivision period(5 days before booting),on the other,the regression coefficients being-0.818 and-0. 622,respectively The fertility transformation in C49S was shown to bemainly determined by Tmin with a secondary regulatory part played by With Tmin lowerthan 7.7C and T lower than 10℃,C49S appeared highly sterile aid its fruiting rate wasless than 4 percent.With Tmin higher than 11.5℃,its fertility tended to return to normallevel and the fruiting rate rose to 50 percent or more.