温光型核雄不育小麦育性转换的温度敏感期和临界温度研究

多年人工气候箱和田间分期播种试验表明，小麦温光型隐性核雄不育两用系C49S育性温度敏感期较长，从花粉母细胞形成期到成熟花粉期都有一定程度的敏感性，其中最敏感的时期有两个，即花粉母细胞减数分裂期和小孢子中期，当减数分裂期温度与小孢子中期温度均较低时，C49S表现为高度不育，当其温度均较高时，C49S表现为高度可育；C49S高度不育的临界温度是关数分裂其平均最低温度（Tmin1）、小孢子中期平均温度（T2）和平均最低温度（Tmin2），分别为8.5℃、13.5℃和10.5℃；C49S高度可育的临界温度是Tmin1 11.5℃、T2 15.0℃、Tmin2 12.5℃；对温光型核雄不育两用系在小麦杂种优势利用中的应用价值、条件及风险进行了综合评价。

Thermo-sensitive period and critical temperature of fertility transition of thermo-photo-sensitive genic male sterile wheat

The thermo-sensitive period and the critical temperature of fertility transition of C49S, a principal thermo-photosensitive genic male sterile line in two-line hybrid wheat, was studied in the growth chambers for controlling temperature and photoperiod. The seeds were sown on different time for some years. The results showed that the thermo-sensitive period in fertility expression of C49S was from PMC formation stage to mature pollen stage, and there were two most sensitive stages to temperature on fertility expression. One was the PMC meiosis stage, and the other was the middle microspore stage. The critical temperatures evoking a complete male sterility were the mean minimum temperature at PMC meiosis stage (Tmin1), the mean temperature at microspore stage (T2) and the mean minimum temperature at microspore stage (Tmin2) lower than 8.5 degrees C, 13.5 degrees C and 10.5 degrees C, respectively. The critical temperatures keeping a nearly normal male fertility Tmin1 and T2 and Tmin2 were higher than 11.5 degrees C, 15.0 degrees C and 12.5 degrees C, respectively. The value as well as the conditions and the risks of thermo-photo-sensitive genic male sterile line of wheat applied to hybrid wheat were evaluated in this paper.