一个水稻长芒基因AWN-2的定位与克隆

Mapping and Cloning of AWN-2 Controlling Long Awn in Rice

本研究在以广西普通野生稻DP30为供体,籼稻品种9311为受体构建的染色体片段代换系中,筛选鉴定出1份稳定遗传的具有长芒表型的染色体片段代换系。利用该代换系与轮回亲本9311构建了BC5F2分离群体,对控制长芒表型的基因进行了遗传分析,发现该群体中长芒与短芒的单株分离比符合3:1的比例,表明该长芒性状受一对显性核基因控制。采用图位克隆法,将目的基因精细定位于水稻第4染色体分子标记M7和M8之间的12.14 kb范围内,该区域只有一个候选基因即LOC_Os04g43840,测序分析发现与栽培稻日本晴、9311相比,CSSL5的LOC_Os04g43840基因在5'UTR区有29个碱基的缺失和2个碱基的置换,因此,推测LOC_Os04g43840可能为该长芒候选基因。

In this study, one accession of Guangxi common wild rice（Oryza rufipogon Griff.） were used as donor parent, and an indica rice varieties 9311 was used as receptor parent, a set of rice chromosome segment substitution lines（CSSLs） had been established, from which we characterized a long awn line CSSL5. In the BC5F2 segregating population derived from the cross between CSSL5 and 9311, the ratio of long awn plants to short awn plants showed 3：1 frequency distribution, suggesting that the long awn phenotype was controlled by a pair of dominant nuclear genes. Using the method of map-based cloning, we located this gene to a 12.14 kb region between markers M7 and M8 on chromosome 4, including only one predicted gene, which was LOC_Os04g43840.Comparison of the coding sequences of the predicted gene in CSSL5, Nipponbare and 9311, we revealed 29 bp deletions and 2 bp mutations of LOC_Os04g43840 in CSSL5. Therefore, we speculate LOC_Os04g43840 is the candidate gene.