一个水稻半矮化突变体基因的初步定位

Preliminary Gene Mapping of a Semi-dwarf Mutant(sd-ch) in Rice

发掘和鉴定控制水稻株高的基因,实现对水稻株高的定向改良,具有重要的理论意义和应用价值。利用甲基磺酸乙酯(EMS)诱变水稻恢复系R30,获得了一个能稳定遗传的半矮化突变体(sd-ch)。将sd-ch作母本,与"泸恢17"进行杂交,构建F2群体,进行遗传分析,并用SSR分子标记对sd-ch进行定位。结果表明,F1表现为正常亲本高度,F2群体株高出现性状分离,正常高度植株和半矮化植株数量分别为401和143,比值为2.8,经卡方检测符合3:1,表明sd-ch受隐性单基因控制;通过SSR分子标记对sd-ch进行定位,第8染色体上SSR标记RM6028从F2群体101个隐性表型单株中检测到2个单交换株,交换率为0.99%。该基因被定位于RM6028附近,遗传距离为0.99 c M。本研究对sd-ch的初步定位,以及对其进行精心定位、克隆和应用奠定了基础。

Realizing directional improvement in plant height of rice by exploring and appraising the genescontrolling it has very important theoretical significance and application value. One semi-dwarf mutant（sd-ch）with stable heredity was originally identified from a rice restorer line of R30 induced by ethyl methanesulfonate（EMS） treatment. Hybridization of sd-ch as female parent and‘Luhui 17＇was produced to establishF2 population. The genetic analysis of sd-ch was conducted, and the gene of sd-ch was mapped using SSRmarkers. The results showed that the performance of F1 was the normal parent＇s height. Trait separation ofplant height was appeared in F2 population. The numbers of normal height and semi- dwarf plant wererespectively 401 and 143. Their ratio was 2.8 and in accord with 3：1 by χ2test. These results showed that sd-ch was controlled by a single recessive gene. The sd-ch was mapped by SSR markers. Two single exchange plantswere checked out from 101 plants with recessive performance of F2 population by the SSR marker of RM6028 on chromosome 8. The exchange percentage was 0.99%. The gene was mapped near marker RM6028. Theirgenetic distance was 0.99 c M. The primary mapping of sd-ch was conducted in this research. These results laida foundation for fine mapping, cloning and application of sd-ch.