珍汕97A和HN5s育性恢复突变的观察

通过^60Co-r辐照与NaN3复合处理及外加成熟胚培养，对得到的珍汕97A和HN5s育性恢复突变体突变率进行了比较，且对育性恢复突变体自交后代不育株的花粉败育类型、光敏不育株的不育特征进行了分析。结果表明不育系经过诱变处理可以发生：1．不育株向可育株的转变；2．不育株的败育类型由典败向无花粉型、圆败及染败的转变；3．光敏不育株可转变为温敏不育株。由此提出光敏核不育系育性漂移主要是不育基因发生育性恢复突变，又在自交、杂交过程中累积的结果。

Observation of Revertants in CMS Line Zhenshan 97A and PGMRs Line HN5s

To compare the differences between the CMS(Cytoplamic Male Sterile Line) Zhenshan 97A and PGMRs (Photoperiod Sensitive Genic Male-Sterile Rice )HN5s in the sensitivity to physical and chemical inducing factors and to study the changes in pollen fertility under inducing conditions, pollen abortive type in the revertants offspring by self polleniation and the rate of fertile mutation ,which was obtained by the combination treatments of 60Co-γ irradiation , sodium azide and mature embryo culture,were observed. The following results were obtained :1) Male-sterile plant was converted into fertile revertants;2)Abortion type of pollen was changed into pollen free or spherical abortion type or stained abortion type;3) Photoperiod sensitive male-sterile plant was changed into thermal sensitive male-sterile plants. Furthermore it was put forward that the shift of sterility in photoperiod sensitive male-sterile rice was resulted from the reversion of the male-sterile gene to fertile gene and the accumulation in the course of self-cross in revertants or crossed with other plants under natural conditions.