一个新的水稻隐性高秆突变体的遗传分析和基因定位

Genetic Analysis and Gene Mapping of a New Recessive Long-Culm Mutant in Rice

【目的】寻找新的水稻隐性高秆基因,为解决水稻不育系的包颈现象及增加恢复系的株高提供重要的遗传资源。【方法】在田间试验时发现一株高秆突变体,经过连续3代的自交和选择后,获得稳定遗传的高秆突变体。突变体的株高比野生型中花11平均增加72.3%。将带有高秆基因的杂合体自交,分析F2代株高的遗传行为,结果表明高秆性状由一对隐性基因控制。分别配制突变体、野生型与培矮64之间的杂交种及其自交F2分离群体,在突变体配制的分离群体中鉴定出72株极端高秆突变体,株高明显高于对照群体中的最高植株高度。【结果】利用均匀分布于水稻12条染色体上的147对多态性分子标记,分析这些标记位点在极端高秆突变体群体中的分离特征,结果证明高秆基因位于水稻第3染色体。进一步发展了4个InDel标记,确定高秆基因位于RM168与M127.1-3-3标记之间,物理距离为713 kb。【结论】该基因是一个新的隐性高秆基因,暂命名为lc3。

【Objective】Make exploration of new recessive long-culm gene to provide important genetic resources of the male sterile lines with better panicle exsertion and of the restorer lines with taller plant height than the control.【Method】An individual plant of long-culm mutant was discovered.After self-cross and selection of three consecutive generations,the long-culm mutant with genetics stability was obtained.The plant height of the mutant was 72.3% higher than that of the wild type parent,Zhonghua11.Genetic analysis of plant height was conducted with the population from self-cross progenies of individuals with heterozygous genotype in the locus of long-culm gene.The results indicated that the phenotype of long-culm trait was controlled by a recessive allele.Two F2 segerating populations from the crosses of long-culm mutant/Pei-Ai 64 for gene mapping and of Zhonghua 11/Pei-Ai 64 as control were developed.Compared the plant height in two F2 populations,seventy two long-culm mutants were selected for the long-culm gene mapping.【Result】One hundred and forty-seven polymorphic molecular markers,evenly distributed on 12 rice chromosomes,were used to map the long-culm gene.After statistical analysis between the genotypes of SSR markers and the phenotypes of individuals,the long-culm gene was mapped on chromosome 3.Four InDel markers were developed and the gene was finally located between RM168 and M127.1-3-3 with 713 kb of the physical distance.【Conclusion】The gene was a new recessive long-culm gene and named as lc3（long-culm 3）.