水稻雄性不育突变体802A的遗传分析及基因定位

Genetic Analysis and Molecular Mapping of the Rice Male Sterile Mutant 802A

【目的】对雄性不育突变体802A进行表型鉴定和遗传分析,并对不育突变基因进行分子标记定位。【方法】调查802A突变体的花粉育性、形态特征和主要农艺性状,同时对其不育性状进行遗传分析,并以802A/Ⅱ-32B F2和802A/02428 F2为定位群体,运用SSR、InDel等分子标记进行基因定位。【结果】802A突变体的花药瘦小、干瘪、不开裂,外观呈乳白色,花粉以典败为主,属于普通雄性不育类型。同时,该突变体还表现颖壳变细、扭曲,剑叶变短、变窄、内卷,穗颈包颈等特征。遗传分析表明,802A的雄性不育性状由1对隐性核基因控制。该不育突变基因定位于第3染色体长臂的SSR引物RM3513附近,InDel标记S2和S5之间,该基因与这2个InDel标记的遗传距离分别为0.6和0.3 cM,并且与InDel标记S3和S4在167株F2不育单株中共分离。【结论】通过与迄今已报道的水稻雄性不育基因比较,认为802A所携带的突变基因是一个新的水稻隐性核不育基因,暂命名为ms92(t)。

[ Objective ] A male sterile mutant 802A was discovered in the Fs population from the crosses between two indica lines, i.e. Shuihui 527 and Shuhui 881. The objective of this study is to conduct phenotypic observation, genetic analysis and molecular mapping of the 802A mutant. [Method] The pollen fertility, phenotypes and major agronomic traits of the mutant were observed. Genetic mapping was conducted by using molecular markers and the F2 mapping population from 802A/11-32B and 802A/02428. [Result] The anther of the 802A mutant was slender and milky-yellow, and remained unbroken after flowering. Its pollen primarily belonged to typical abortion type. Meanwhile, the mutant showed that the glumes were thinned and twisted; the flag leaves were narrowed, shortened and frizzled; the basal part of panicles was enclosed in the sheath. Genetic analysis suggested that the male sterility of the 802A mutant was controlled by a pair of recessive nuclear genes. The gene for male sterility is located on the long arm of rice chromosome 3, nearby SSR marker RM3513, between InDel markers S2 and S5. The genetic distances from the target gene to the two InDel markers were 0.6 and 0.3 cM, respectively. At the same time, the mutant gene co-segregated with InDel markers S3 and S4 in 167 F2 male sterile individuals from the mapping population. [Conclusion] Compared with the known male sterile genes, the mutant gene of 802A was considered to be a novel recessive male sterile gene in rice, and was designated tentatively as ms92（t）.