稻瘟病抗性基因Pita特异性分子标记的开发及应用

Development and Application of Specific DNA Marker for Rice Blast Resistance Gene,Pita

Pita是一个具有广谱抗性的稻瘟病抗性基因,已经被引入到各稻区的抗性育种工作中。在基于分子标记辅助选择的水稻抗性育种工作中,为了提高对Pita的筛选效率,本研究以导致Pita第918个氨基酸发生变异的单碱基差异为靶标,开发得到Pita基因特异性分子标记,Pita918。研究结果表明,Pita基因特异性分子标记能准确地将Pita与各抗性基因及感病等位基因区分开,这将为育种家提供了直接而高效的Pita筛选标记。同时,本研究还利用该标记对收集自华南及西南稻区的13个水稻地方抗性品进行基因检测,结果显示这13个品种均不携带有抗性基因Pita,表明Pita基因特异性分子标记在水稻抗性材料的基因型鉴定中具有应用价值,有助于育种家挖掘新的抗性基因材料。

Pitu is a broad-spectrum resistance gene for rice blast and has been applied in different rice resistance breeding programs. In order to improve the efficiency for Pita selection based on molecular marker-assistant selection （MAS）, a gene-specific dCAPs marker, Pita918, targeted on single nucleotide polymorphism that result in single amino acid changed between resistant and susceptible allele of Pita on 918th aa has been developed in this paper. The result showed that Pita specific DNA marker Pita918 can distinguish Pita from other R genes and susceptible allele gene clearly, providing breeders an efficient and accurate marker for Pita selection. Additionally, Pita918 has been used for genotype characterization among 13 resistant rice landraces collected from south and southwest of China, the result showed that those landraces do not harboring Pita for their rice blast resistance, suggesting that Pita918 is a valuable DNA marker for genotype identification in rice germplasm, which will give breeders abundant genetic information in new resistance genes discovery.