水稻光(温)敏雄性不育系的育性转换机理研究

A Preliminary Study of the Fertility Change Mechanism of the Photoperiod (Temperature Period) Sensitive Genie Male Sterile Rice (PSGMR)

光敏核不育水稻的育性转换是由抽穗前5至15—20天的光温条件综合作用的结果。可育期内育性表现为一偏向高温（长日）的单峰型曲线,其数量关系可由结实率量化模型表达。温敏型不育系的育性变化由温度主控,光敏型不育系的育性在日长大于最适日长时由日长主控,短于最适日长时由温度主控,光温敏型不育系的育性由温光条件共同作用。温光当量可作为比较温度和日长对育性影响大小的具体量值。育性转换是一个可逆连续过程,其恢复和降低的程度取决于日长和温度变化的强度和持续时间。根据育性转换机理和光温条件的时空变化规律,育性转换期也具有显著的气候学特征。温敏型不育系的育性转换期波动大,只有育性转换临界温度幅度较大的不育系才可能有较广泛的适应性。光（温）敏型不育系的育性转换期波动较小,只要育性转换临界日长较长,最适日长较短,就具有较高的利用价值。

The fertility change of the GMR is determined by the phototemperature condition in the period from 5 days to 15-20 days before heading stage. In the bearing period, the fertility can be presented by a single peak curve with its peak value leaning to the higher temperature (longer solar duration). The fertility of the temperature sensitive GMR is mainly controled by the temperature. The fertility of the photo-sensitive GMR is controled by the solar duration when the solar duration is longer than the optimum solar duration and controled by temperature when the solar duration is shorter than the optimum solar duration. The fertility of the photo-temperature sensitive GMR is controled both by the solar duration and the temperature. Photo-temperature equivalent may be used to compare the effects on the fertility caused by the temperature with that caused by the solar duration. Fertility change is a revesible and successive course. The resumation and reduction degree of the fertility are decided by the intensity and continued days of the temperature and solar duration. The fertility change date has obvious climatic characteristics. The fertility change dates of the temperature sensitive GMRs fluctuate greatly and only those whose fertility change critical temperature range are big may have wide adaptations. The fertility change dates of the photo-sensitive and photo-temperature sensitive GMRs fluctuate little and they will have higher utilization values when the fertility change critical solar durations are long and the optimum solar durations are short only.