稻瘟病抗病基因Pi-k^h功能标记的开发及江苏粳稻品种中Pi-k^h的变异

Development of a Functional Marker for Rice Blast Resistance Gene Pi-k^h and Natural Variation at Pi-k^h Locus in japonica Rice in Jiangsu Province,China

稻瘟病抗病基因Pi-kh是对稻瘟病菌具有广谱抗性的一个重要基因。根据Pi-kh感病基因和抗病基因序列存在143bp插入的特征,设计了InDel标记FM143。Tetep具有抗病基因Pi-kh,分子标记FM143PCR扩增带型为非插入带型,而不携带Pi-kh的材料的带型为插入带型。利用该标记对Tetep与宁9108的F2群体进行分析,结果表明该标记能准确区分Pi-kh、Pi-kh纯合及杂合基因型,标记基因型符合1∶2∶1比例,没有发生偏分离现象。利用该标记对65份江苏省历年来大面积推广的粳稻品种和64份粳稻品系进行检测,筛选出具有非插入带型的粳稻品种19份、粳稻品系22份。进一步对江苏省粳稻品种中Pi-kh位点进行测序,发现江苏粳稻品种(系)Pi-kh基因座位与Tetep和已经登录的Pi-kh序列相比在102bp处存在一个单碱基的变异(由G突变为C),使得谷氨酸变异为天门冬氨酸,且该变异高度保守。将江苏省粳稻品种中发现的Pi-kh位点的等位基因暂定名为Pi-khJSJ。

Pi-kh is a vital non race-specific resistance gene for rice blast.In this study,one InDel marker,FM143 was developed based on the 143 bp insertion between the susceptible and resistant Pi-kh alleles.Previous studies showed that Tetep carried resistant Pi-kh allele and had the none-insertion genotype for PCR by FM143.F2 population,derived from Tetep and Ning 9108,were detected by marker FM143 and the result indicated that FM143 could effectively identify Pi-kh/Pi-kh ,Pi-kh/pi-kh and pi-kh/pi-kh genotypes with the expected segregation ratio 1∶2∶1.Sixty-five japonica varieties widely grown in Jiangsu Province over years and sixty-four japonica lines were genotyped by FM143. Among them,19 japonica varieties and 22 japonica lines showed none-insertion genotype.Further sequencing at the target Pi-kh locus for these none-insertion genotype showed that there was one highly conserved single-base mutation （G→C）at 102 bp location compared with the whole target gene sequence in Tetep and public Pi-kh GeneBank leading to the changes fromg lutamic acid to asparaginic acid.This new allele in Jiangsu japonica rice was termed as Pi-khJSJ.