目的 揭示航天诱变水稻雌性半不育的变异特性。方法 以常规籼型水稻‘秋B’(野生型)航天搭载诱变获得的雌性半不育突变体rs(s)为研究对象，对其开展形态学、细胞学、生理学和遗传学研究。调查突变体与野生型及其正反交F1、F2群体结实率，对亲本的花粉和胚囊育性进行细胞学观察，测定突变体与野生型幼穗生长素(IAA)、细胞分裂素(TZR)、脱落酸(ABA)和赤霉素(GA3)的含量变化。结果 突变体rs(s)雄蕊发育正常但雌性半不育，该性状受隐性单基因调控；发育过程中子房干瘪瘦小，柱头伸长不明显，雌蕊在胚囊发育的有丝分裂阶段发生异常，导致胚囊败育；IAA含量在突变体幼穗分化第6阶段急剧增加。结论 突变体rs(s)是一个新的雌性半不育突变体，在有丝分裂阶段生长素含量急剧增加，可能抑制了雌蕊的生长发育，导致雌蕊发育畸形、雌性半不育。
Objective To reveal the variation characteristics of female semi-sterility in rice induced by space flight. Method The morphologic, cytological, physiological and genetic characteristics of a female semi-sterile mutant rs(s) obtained in conventional indica rice ‘Qiu B’ through space flight mutagenesis were studied. The setting rates of the mutant and its wild type, as well as their reciprocal cross F1 and F2 populations, were investigated. Cytological observations of pollen and embryo sac fertility of the mutant and the wild type were conducted. The content changes of auxin (IAA), cytokinin (TZR), abscisic acid (ABA) and gibberellin (GA3) in young ears of parents were determined. Result The mutant rs(s) was female semi-sterile and it had normal stamen development, indicating the semi-sterility might be controlled by a single recessive gene. During the development, the ovary was shrift and thin, the elongation of the stigma was not obvious, and the pistil was abnormal in the mitotic stage of embryo sac development, which leaded to embryo sac abortion. The content of IAA increased sharply at the 6th stage of young panicle differentiation. Conclusion The mutant rs(s) is a new female semi-sterile mutant. The auxin content is up-regulated in the mitotic stage, which may be the main cause of pistil development malformation and female semi-sterility.