水稻苗期耐盐突变体的遗传分析及基因定位

Genetic analysis and gene mapping for a salt tolerant mutant at seedling stage in rice

在籼稻品种R401辐射诱变的M2群体中筛选到一个苗期耐盐突变体,在150mmol/L的NaCl溶液处理下对照植株枯萎死亡,而突变体植株依然存活。以粳稻品种Nipponbare(不耐盐)和耐盐突变体作亲本,构建了一个F2群体,调查该群体在150mmol/L的NaCl溶液胁迫下的表现,发现Nipponbare和耐盐突变体苗期耐盐性的差异受单个主基因控制,耐盐为隐性,将该基因暂时命名为SST(t)。利用该F2群体,采用集团分离分析(Bulked segregant analysis,BSA)法将SST(t)定位在第6染色体上,进一步对F2群体中137个典型的耐盐单株的分子标记进行分析,将该基因定位在InDel标记ID26847和ID27253之间,约2.3cM(或406kb)的区间内,与两标记分别相距1.2cM和1.1cM。

A salt tolerant mutant at seedling stage was obtained from an M2 population of radiation mutagenesis of an indica rice cultivar R401. The mutant seedlings could survive under the treatment of sodium chloride solution at the concentration of 150 mmol/L, while the wild-type control seedlings withered and died. An F2 population was developed from a cross between a japonica cultivar Nipponbare and the salt tolerant mutant. By investigating the performance of the F2 population under the stress of 150 mmol/L NaC1 solution, we found that the mutant phenotype was caused by the recessive mutation of a single gene, temporarily designated SST（t）. Bulked segregant analysis （BSA） based on the F2 mapping population revealed that SST（t） is located on chromosome 6. By analyzing 137 typical salt-tolerant F2 plants using molecular markers, SST（t） was mapped in a 2.3 cM （or 406 kb） interval between InDel markers ID26847 and ID27253, with genetic distances of 1.2 cM and 1.1 cM to the two markers, respectively.