水稻白化转绿基因Gra3的精细定位及遗传分析

Genetic and Fine Mapping of a Rice Green-revertible Albino Gene Gra3

本研究鉴定到一份水稻苗期白化转绿突变体,该突变体在幼苗的2叶到4叶期会出现叶片边缘白化,4叶期后转绿,对突变体和野生型农艺性状比较研究表明,前期白化不会对植株生长发育及产量等相关性状产生影响;同时,对两者叶绿体超微结构对比分析发现,突变体叶绿体发育在白化期受到一定程度的抑制。通过构建F2分离群体,调查了部分F2单株表型,结果表明白化型和野生型单株符合1:3的孟德尔单基因分离比,遂将该基因命名为Gra3;利用分离群体分析法(bulked segregant analysis,BSA)和隐性群体分析法(recessive-class analysis,RCA)最终将Gra3定位于RM14436和RM14450之间,对应日本晴基因组片段125 kb。该性状可作为一个形态学标记应用于水稻生产。

A rice green-revertible albino mutant at seedling stage was identified and it behaved albinotic leaf edge at 2-4 leaf stage but reverted to green after 4-leaf stage. The comparison of agronomic traits between wild-type and mutant showed that there were no significant difference with yield, growth and development related traits.Ultrastructure of chloroplast in wild-type and mutant behaved that chloroplast development was suppressed to some extent at albino stage. F2 segregation population was constructed and some of their phenotype was observed.The results showed that it fitted well for 1:3 single gene segregation and then named it Gra3. In the end Gra3 was mapped between RM14436 and RM14450 corresponding to 125 kb in Nipponbare genome using bulked segregant analysis and recessive-class analysis. This trait can be used as a morphological markers in rice production.