浙粳22类病斑突变体spl(t)特征及其基因定位

在浙粳22辐照的突变体库中,筛选出一个对环境不敏感的全生育期表达的类病斑突变体。遗传分析表明,该突变性状由1对隐性核基因spl(t)控制。利用SSR标记对类病斑突变体spl(t)与珍汕97B杂交构建的F2群体进行基因定位,把spl(t)基因定位在第12号染色体短臂端的着丝粒附近,位于SSR标记RM7195与RM27929之间的0.8cM区间内。锥虫蓝染色检测结果表明spl(t)类病斑的形成和发展是一个程序性细胞死亡的过程。进一步研究表明,这种程序性细胞死亡是由H2O2氧迸发而致。突变体经白叶枯病和稻瘟病鉴定,表明该突变体的抗病性与野生型品种浙粳22相仿。

Characterization and Genetic Mapping of a Lesion Mimic Mutant spl(t) in Japonica Rice Variety Zhejing 22

A lesion mimic mutant, obtained by radiation mutagenesis on the seeds of a japonica rice variety Zhejing 22, exhibited a lesion mimic phenotype during the whole growth stage under different environments. Genetic analysis indicated that the mutant trait was controlled by a single recessive gene named spl(t). Relying on simple sequence repeat (SSR) and recessive class analysis method to map the spl(t) gene with a F2 population was constructed by crossing the mutant spl(t) with Zhenshan97B. spl(t) was mapped in the interval of 0.8cM between RM7195 and RM27929 near centromere region on the short arm of chromosome 12.  Blue dyed trypan analyses indicated that the lesion mimic trait of the mutant was caused by the programmer cell death. Further study showed that the programmer cell death was caused by H2O2 oxidative burst.  By inoculation of bacterial leaf blight and blast strains, the resistances of the mutant were similar to the wild variety Zhejing 22.