稻瘟病抗性基因 Pi2、Pita 的特异 KASP 标记开发与应用

【目的】水稻稻瘟病抗性基因 Pi2 和 Pita 是对华南稻区稻瘟病生理小种具有广谱抗性的基因，对水稻的稻瘟病抗性育种具有重要应用价值，开发一套高效的鉴定方法有利于提高水稻抗病品种培育效率。【方法】根据高抗稻瘟病品种‘黄广油占’与高感稻瘟病品种‘广陆矮 4 号’在 Pi2 基因的第 787 位、第 788 位密码子上的变异 GCA GGA/GTG TTA，以及高抗稻瘟病国际稻种质资源 Tetep 与高感稻瘟病地方种质资源丽江新团黑谷在 Pita基因第 6 640 位碱基上的变异 G/T，基于竞争性等位基因 PCR（Kompetitive Allele Specific PCR，KASP）标记技术原理，开发抗稻瘟病基因的分子标记。【结果】开发了两个抗稻瘟病基因 Pi2 和 Pita 的功能位点 KASP 标记（W-Pi2、W-Pita），利用标记对广东省农业科学院水稻研究所培育的常规稻、香稻、杂交稻新品种进行检测，筛选出抗性品种 19 个，其中单个基因检测为抗病等位基因型的水稻品种有 13 个，两个基因均为抗病等位基因型的品种有 6 个，比较两个标记结果，Pi2 抗性等位基因在育成品种中的频率高于 Pita 抗性等位基因频率。综合所有结果，表明 2 个标记可在早期（种子或苗期）检测育种材料抗稻瘟病基因 Pi2 和 Pita 的等位基因型，无需将育种材料种植到病圃鉴定即可筛选出抗病单株。【结论】利用开发的 KASP 功能分子标记 W-Pi2、W-Pita 能够较好区分不同抗性的水稻亲本品种，可清楚区分水稻育种材料间不同的等位基因型，对育种材料进行准确筛选。

Development and Application of Specific KASP Markers for Blast Resistance Genes Pi2 and Pita in Rice

【Objective】 Rice blast resistance genes Pi2 and Pita are broad-spectrum resistance genes to rice blast in rice areas in South China, which have very important application value for rice blast resistance breeding. Therefore, the development of a set of efficient identification methods is beneficial to genetic breeding efficiency of rice blast-resistant varieties.【Method】According to the variant GCA GGA/GTG TTA of the 787 and 788 codons of the Pi2 gene in ‘Huanghuangyouzhan’ (highly resistant to rice blast) and ‘Guangluai 4’ (highly susceptible to rice blast), and the variant G/T at base 6 640 of Pita gene in Tetp (an international rice germplasm resource with high resistance to rice blast) and Lijiang Xintuan Heigu (a local ermplasm resource with high susceptibility to rice blast), based on the competitive allele PCR (Kompetitive Allele Specific PCR, KASP) labeling technology principle, molecular markers of rice blast resistance genes were developed.【Result】Two KASP markers (W-Pi2 and W-Pita) were developed to detect the functional sites of Pi2 and Pita. The markers were used to detect the conventional rice, aromatic rice and hybrid rice cultivated by the Rice Research Institute of Guangdong Academy of Agricultural Sciences. 19 resistant varieties were screened, including 13 varieties with a single gene tested as a disease-resistant allele and 6 varieties with two genes tested as disease-resistant alleles. The comparison of the two markers suggested that the frequency of disease-resistance was higher in the varieties carrying Pi2 resistance gene than in the varieties carryingPita resistance gene. The results showed that the two markers could detect the allele types of rice blast resistance genes Pi2and Pita in breeding materials in the early stage (seed or seedling stage), and the breeding materials were not required to be planted in the disease nursery, then individual plants carrying resistant alleles could be screened and identified.【Conclusion】The developed KASP functional molecular markers W-Pi2 and W-Pita can better distinguish parental varieties with different resistance, clearly distinguish different allele types among breeding materials, and accurately screen breeding materials.