T-DNA插入产生的水稻小粒突变体遗传分析

Genetic Analysis of Small Grain Mutant Induced by T-DNA Insertion in Rice

[目的]研究水稻粒形突变体的遗传特性及其在水稻遗传改良中的作用。[方法]筛选水稻T-DNA插入纯合体,鉴定表型变异,通过表型突变的遗传分析及其与T-DNA插入共分离的检测,研究水稻表型突变的遗传特性。[结果]观察到1个粒形突变体T56。主要表现为粒长变短、粒宽变窄及千粒重降低;对该突变体进行遗传分析,分离群体出现野生型和突变体2种类型,其分离比符合3∶1,表明该突变体表型受1对隐性基因控制。突变体及其后代分离群体的Basta抗性检测和PCR分子检测结果表明,该突变体由T-DNA插入所引起,突变性状与T-DNA共分离。[结论]该材料可用于插入座位的基因克隆和水稻遗传改良的种质资源。

[Objective] The aim of this study was to understand the genetic characteristics of a grain shape mutant and its possible role in genetic improvement of grain yield in rice.[Method] On the basis of the collection of T-DNA tag lines,the progeny of homozygous plants carrying T-DNA insertion were screened for mutants with mutated phenotypes.The genetic analysis of the mutant and test for the linkage between the mutated phenotype and the T-DNA insertion were carried out to determine its genetic characteristics.[Result] In the present study,a grain shape mutant induced by T-DNA insertion in rice was identified,which showed small grain in mutants.Genetic analysis of the mutant showed that the two types of phenotype,normal and small grain in the segregating populations derived from the T-DNA heterozygotes,fiting the ratio of 3∶1.Test for Basta resistance showed that all of the mutants were resistant while the normal plants segregated for resistant and susceptible by the ratio of 2∶1.The results indicated that the mutant phenotype co-segregated with Bar gene.The small grain mutant caused by T-DNA insertion was confirmed by PCR amplification aiming at T-DNA.[Conclusion] The grain shape mutant is useful for isolation of the tagged gene and genetic improvement in rice.