A Study On Thermo-photosensitivity Characteristic Of Fertility Transfer Of Dual-purpose Genic Male Sterile Line Of Sorghum At High Critical Temperature

The purpose of this experiment was to deal with the problem of fertility unstability in seed production of two-line sorghum. The fertility appearance of the Dual-purpose Genie Male Sterile(GMS) line must meet the requirment for the strict thermo-photoperiod condition during the special growth period. The purification and stable characteristic and the sensitive period of GMS line of sorghum, effect of temperature and photoperiod on it's fertility transfer and molecule mechanism were studied by using phytotron, field experiment and isoenzyme and protein analysis. The results follow as:1. The GMS line of Xiangnuoliang 2S appeared stable sterile at 25℃ at heading stage, and both of sterile plant rate and abortive pollen rate were 100%.The ratoon plants cut down from sterile plants at 26℃ displayed the fertility alternation plant at 28℃, and breed the purificatory and stable GMS line's seed. Xiangnuoliang S-1 appeared fertility at 25℃.2. Sensitive period for fertility transfer of the Xiangnuoliang 2S ranged from pollen mother cell differentiation to meiosis, morphylogically the stage when the leaf ring of the flag leaf is 0.8cm higher then that of the second leaf from the bottom, i.e., 4-10 days(in autumn) or 3-7 days(insummer) before heading.3. The critical temperature of fertility transfer of Xiangnuoliang 2S was 25C, and the plant appeared sterile under lower temperature and fertility under higher temperature.4. Photoperiod had certain effect on the fertility transfer of Xiangnuoliang 2S, The day-short was benefical to sterility but day-long to fertility.5. Seeding stage of hybrid seed production in Sanya, Hainan of the Xiangnuoliang 2S in winter was from the third ten days of September to November, heading stage was from the third ten days of November to next January. The fertility of plant appeared stable during this period, the sterile plant rate reached to 100%, the abortive pollen rate reached to 99.8%. Seeding stage of hybrid seed production for high altitude in summer was from the first ten days of June to the second ten days of August in Fenhuang, Hunan. The fertility of plant appeared stable during this period, the sterile plant rate reached over 98.6%, the abortive pollen rate reached over 98.2%. Seeding stage of multipication in Changsha, hunan was from the third ten days of April to May, heading stage was from the second ten days of July to August. Xiangnuoliang 2S was fertility when temperature was over 28C during this period.6. Activity of peroxide enzyme of sterile material of the Xiangnuoliang 2S was higher than that of other fertility material, and the sterile materialincreased 92KD polypeptide through analysising to isoenzyme and protein's electrophoresis. The results showed that this sterile might be male fertility gene's expression in thermo-photosensitivity modulatory was set back leading to pollen abortivity.