Abstract: 【Objective】A male sterile mutant 802A was discovered in the F8 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/Ⅱ-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).

Key words: Rice (Oryza sativa L.), Male sterility, Genic male sterility, Genetic analysis, Gene mapping