Abstract: Segregation of seed setting in the F₂ population of a cross of Nongken 585, a japonica photoperiod-sensitive male sterile rice line, with Nongken 58, the original fertile parent of Nongken 585, was repeatedly observed under the natural conditions of Hangzhou (30°05'N) in the summers of 1989 and 1992, respectively. Distinctly yearly discrepancy in seed setting segregation in the F₂ population was found. The rate of fertile plants was higher in 1989, when abnormally low temperature occurred during the summer, than in 1992. Smirnov test indicate that distribution of two observed data is different (P< 0.01 ). which is attributed to the effect of temperature on the expression of the photoperiod-sensitive male sterility. It is suggested that current methodology for genetic research on photo- or thermo-period sensitive male sterility in rice under natural conditions be unsuitable due to instability of temperature change. A new approach to study it is proposed.

Key words: Genetics, Photoperiod-sensitive male sterility, Fertility, Segregation

摘要： 分别于1989和1992年盛夏在杭州（30°05' N）自然条件下观察了农垦58 F₂群体的育性分离情况。结果表明，该组合F₂群体育性分离模式年度间差异大，在1989年凉夏期间群体内育性分离偏于可育部分，而在1992年炎夏期间则偏于不育侧。斯米尔 诺夫检验表明，上的育性分布差异明显（P＜0.01）。这种育性分离模式的年度间偏差被归为环境温度等条件对光敏雄性不育遗传表达影响的结果。认为在自然条件下应用经典遗传学方法研究光温敏雄性不育的遗传是不合适的，提出了深入研究光温敏雄性不育遗传的可能性。

关键词: 遗传, 育性, 分离, 水稻, 杂种二代, 光温敏雄性不育