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 diseaseresistant 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 carrying Pita resistance gene. The results showed that the two markers could detect the allele types of rice blast resistance genes Pi2 and 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.