中文摘要：

通过甲基磺酸乙酯诱导粳稻品种日本晴,筛选到一个能稳定遗传的苗期长根突变体 lr1（long root 1）.在发芽后2、4、6、10和15 d,lr1的主根长度分别比日本晴野生型主根长1．52、1．93、3．93、6．81和6．77 cm,根冠比也显著大于野生型.遗传分析结果表明该基因受一对隐性单基因控制.利用 SSR 分子标记将该突变基因 LR1定位于第10染色体长臂上,位于标记 RM304和 RM7300之间,遗传距离分别为2.0 cM 和3．5 cM.

英文摘要：

A seedling long root mutant named lr1 （long root 1 ） was isolated from rice cultivar Nipponbare by mutagenesis with ethyl methanesulfonate （EMS）and the long root trait can be stably inherited.The main root in lr1 mutant was 1 .52,1 .93,3.93,6.81 and 6.77 cm longer than those of wild type at 2,4,6,10 and 1 5-day after germination,respectively,and the root-shoot ratio of lr1 mutant was also significantly greater than that in the seedling of Nipponbare.Genetic analysis indicated that the seedling long root mutant phenotype was controlled by a single recessive gene.The LR1 gene was located between the SSR markers RM304 and RM7300 on chromosome 10,and the genetic distance is 2.0 cM and 3.5 cM,respectively.