Specific molecular markers for detecting the alleles of Pi2/Pi9/Pizt, designated as Pi2SNP, Pi9SNP and PiztPA, respectively, have been successfully developed through sequence comparison method. These three specific markers can distinctly distinguish target genes from others mapped on Pi2/9 locus, which facilitate the molecular markerassistant selection and the development of pyramiding cultivars combined with other allele R genes. Additionally, 101 main cultivars and breeding parents collected from different riceplanting areas have been diagnosed with these three specific markers, and the results showed that only 2 out of 101 cultivars carried Pizt, but neither Pi2 nor Pi9 band had been detected. So far, it indicated that most of the main cultivars and breeding parents in China do not carry Pi2/Pi9/Pizt. These results had provided important information for the application of Pi2/Pi9/Pizt in the blast resistance breeding programs.
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