水稻短根突变体Osksr6的遗传分析和基因定位

该研究对从甲基磺酸乙酯(EMS)诱变的水稻突变体库中筛选到的一个短根突变体Osksr6(Oryza sativa kasalath short root 6)进行了表型鉴定、遗传分析与基因定位。结果表明:(1)生长7d的突变体Osksr6与野生型相比,株高与不定根数量差异不明显,但主根变短61.98%、不定根变短46.42%,侧根的发生与根毛的伸长也受不同程度抑制;成熟期的Osksr6分蘖数明显减少,总穗长与结实率均较野生型差。(2)遗传分析结果显示,突变体Osksr6的短根性状受1对隐性基因控制。(3)利用图位克隆技术,将突变基因OsKSR6定位于3号染色体InDel标记28420k和28880k之间,物理距离约460kb,该区间没有已报道的与根系发育相关的基因。该研究为进一步研究水稻根系生长的分子机理奠定了基础。

Genetic Analysis and Gene Mapping of a Short Root Mutant Osksr6 in Rice (Oryza sativa L.)

A rice short root mutant Osksr6 was identified from an ethylmethane sulfonate (EMS) mutagenized rice library. Phenotypic observation, genetic analysis and gene mapping analysis of Osksr6 were carried out. Results showed that: (1) at the 7 d old stage, there was no significant difference in plant height and the number of adventitious roots between the wild type and Osksr6, while the length of primary and adventitious roots of Osksr6 was decreased by 61.98% and 46.42% compared with the wild type, respectively. Furthermore, the development of lateral roots and root hairs in Osksr6 was also inhibited to varying degrees. At the maturation stage, the tiller number of Osksr6 significantly decreased, and the panicle length and seed rate of Osksr6 were also reduced. (2) Genetic analysis showed that the mutant phenotype was controlled by a single pair of recessive nuclear gene. (3) Map based cloning analysis located OsKSR6 to a 460 kb region between newly designed InDel markers 28420k and 28880k on chromosome 3. There is no gene reported to be involved in root development in this region. This result will be helpful for the cloning of OsKSR6 and further characterization of molecular genetic mechanisms underlying root architecture in rice.