Genetic Analysis and Mapping of a Novel Short Root Hair Gene OsSRH3 in Rice

Root hair is an important organ for uptaking nutrients and water in plant. A rice (Oryza sativa L.) mutant, ossrh3, with short root hairs was isolated from a T-DNA insertion mutant library of rice on Zhonghua 11 background. The elongation of root hairs in the mutant was severely impaired. Beside, some other traits were also affected, such as plant height, primary root length, lateral root length, and number of lateral roots. Genetic analysis indicated that the mutated phenotype was controlled by a single recessive nuclear gene. An F2 population was developed by crossing the mutant ossrh3 with an indica cultivar, Kasalath, to map the gene. Using simple sequence repeat (SSR) markers and newly designed sequence-tagged site (STS) markers, the target gene, OsSRH3, was located to a 37.7 kb region between markers S38978 and S39016 on chromosome 1. This marker interval contained 8 predicted genes.

摘 要根毛是植物吸收水分和养分的重要器官。本研究从T-DNA突变体库中获得一个以中花11为遗传背景的水稻短根毛突变体, 命名为ossrh3 (Oryza sativa short root hair 3) 。该突变体的根毛伸长严重受阻, 并且伴随株高、主根长、侧根长和侧根数目等性状的改变。遗传分析表明该突变性状受1对隐性单基因控制, 利用ossrh3纯合体和籼稻品种Kasalath杂交构建F2定位群体, 利用已公布的水稻SSR (simple sequence repeat) 和自行设计的STS (sequence-tagged site) 标记, 最终将OsSRH3定位在水稻第1染色体上的标记S38978和S39016之间, 物理距离约为37.7 kb, 包含8个候选基因, 为进一步克隆OsSRH3基因和研究禾本科作物根毛发育的分子调控机制提供了依据。