水稻抗稻瘟病基因Pi2的KASP标记开发与应用

【目的】水稻稻瘟病抗性基因Pi2对稻瘟病生理小种具有广谱抗性，开发Pi2的KASP分子标记并对其评价，为抗稻瘟病水稻品种分子育种提供简便、可靠的基因分型检测方法。【方法】利用593份自然群体中筛选出的不同抗性和亲缘关系的2份材料H-74和H-78，针对Pi2基因核心区域的SNP位点开发成KASP标记Pi2-C3。【结果】利用标记Pi2-C3对自然群体中的84份材料进行KASP基因分型，结果表明，该标记可以准确地将不同水稻材料的Pi2位点分为抗病基因型、杂合基因型和感病基因型，是一种高效鉴定抗稻瘟病基因Pi2的方法。利用标记Pi2-C3对阳江市病圃材料进行检测，结合表型调查结果发现，检测到含有Pi2基因的46份材料均表现出不同程度的稻瘟病抗性，表明该标记可以用于检测材料在病圃的发病情况。【结论】本研究采用KASP技术，开发了能准确检测Pi2基因的特异性分子标记Pi2-C3，并建立一套水稻Pi2基因的KASP基因分型体系，对提高抗性育种效率，改良抗稻瘟病水稻品种具有重要应用价值。

Development and application of KASP marker for rice blast resistance gene Pi2

Objective The rice blast resistance gene Pi2 has broad spectrum resistance to physiological race of rice blast. Developing and evaluating KASP molecular markers for Pi2 will provide a convenient and reliable gene typing method for molecular breeding of rice varieties with blast resistance. Method Two materials H-74 and H-78 with different resistance and genetic relationships selected from 593 natural populations were used to develop KASP marker for the SNP sites in the core region of the Pi2 gene, named Pi2-C3. Result Using the marker Pi2-C3, 84 materials from the natural population were genotyped, and the results showed that the Pi2-C3 marker accurately distinguished the Pi2 loci of different rice materials into resistant, heterozygous, and susceptible genotypes, which was an efficient method for identifying the blast-resistant gene Pi2. The marker Pi2-C3 was used to detect the materials in Yangjiang disease nursery. Combined with the phenotypic investigation, it was found that 46 materials containing Pi2 gene showed different degrees of rice blast resistance, which indicated that the marker could be used to detect the incidence of materials in disease nursery. Conclusion This study develops a specific molecular marker Pi2-C3 for accurately detecting the Pi2 gene using the KASP technology, and establishes a KASP genotyping system for rice Pi2 gene. It has important application value for improving the efficiency of resistance breeding and improving blast-resistant rice varieties.