Abstract: A short root mutant ksr1 with the Kasalath background was isolated from an EMSmutagenized population in rice. The root length of 6dayold ksr1 plants was only about 20% of the wild type. Genetic analysis indicated that the short root phenotype of ksr1 was controlled by a recessive mutation in a single nuclearencoded gene. To map the ksr1 mutation, an F2 population was generated by crossing the ksr1 mutant with Nipponbare. The KSR1 locus was linked to the SSR marker RM1223 on chromosome 4. Another eight SSR markers and two InDel markers were developed around this marker. The KSR1 gene was further mapped to a 155 kb region, flanked by the InDel marker 424725K and the SSR marker RM17182.

Key words: rice, short root, gene mapping, molecular marker

摘要： 从甲基磺酸乙酯诱变的Kasalath突变体库中，在苗期筛选到一个水稻短根突变体 ksr1， 6 d苗龄时该突变体的根长只有野生型的20%左右，遗传分析表明该突变性状由一对隐性核基因控制。利用突变体与粳稻日本晴杂交发展的F2群体对突变基因进行了定位分析，初步定位结果显示目的基因 KSR1 与第4染色体上SSR标记RM1223连锁。在该标记附近进一步发展了8对SSR标记和2对InDel标记，将突变基因定位于InDel标记424725K和SSR标记RM17182之间，该区段物理距离为155 kb。

关键词: 水稻, 短根, 基因定位, 分子标记