水稻短根突变体Osksr5的遗传分析和基因定位

Genetic Analysis and Gene Mapping of a Short Root Mutant Osksr5 in Rice(Oryza sativa L.)

水稻根系对其生长、发育及产量等起着至关重要的作用。该研究从甲基磺酸乙酯(ethyl methane sulfonate,EMS)诱变的籼稻Kasalath突变体库中筛选到1个根系变短的突变体,命名为Osksr5(Oryza sativa kasalath short root 5),该突变体植株具体表现为主根、不定根和侧根都明显变短,不定根的数目相对减少,株高与野生型相比也明显矮小。遗传分析结果表明,该突变性状由1对隐性核基因控制。利用图位克隆技术将OsKSR5基因定位在第1染色体的STS(sequence tagged site)分子标记33027k和33471k,物理距离约为444kb。对OsKSR5基因的定位为进一步克隆该基因和阐明水稻根系发育的分子机理奠定了基础。

The root system plays vital roles in plant growth,development and yield.In this study,a rice mutant with significantly short roots was isolated from an EMS（ethyl methane sulfonate）generated rice mutant library in the Kasalath background,designated as Osksr5（Oryza sativa kasalath short root 5）.Osksr5 showed a dwarf phenotype,the elongation of primary roots,adventitious roots and lateral roots in the mutant was severely impaired,and the number of adventitious roots was reduced.Genetic analysis indicated that the mutant phenotype was controlled by a single recessive nuclear gene.Map-based cloning analysis located OsKSR5 to a 444 kb region between STS（sequence tagged site）markers 33027 kand 33471k on chromosome 1.This result will be helpful for the cloning of OsKSR5 and further characterization of molecular genetic mechanisms underlying root architecture in rice.