Analysis of the antimicrobial spectrum of three rice blast resistance genes at Pi2/9 locus and genetic diversity of rice blast strains

In this study,35 blast strains,rice lines including the donors of blast resistant genes and rice transgenic lines with the genetic background of Nipponbare were employed for antimicrobial spectrum analysis of three blast resistant genes Pi9,Pi2 and Pizt.The results showed that Pi9 and Pi2 both have a broad spectrum of resistance with a resistance frequency of 94.2%,while Pizt have a narrow spectrum of resistance with a resistance frequency of only 60%.The blast strains ROR1,X2007A–7 are compatible to Pi9,and CHNOS60–2–3,RB14 are compatible to Pi2.In addition,13 pairs of SSR markers were used for analysis of the genetic diversity of 20 out of the 35 blast strains,the results showed these 20 strains were classified into 4 lineages which showed certain relationship with pathogenicities but no significant correlation with the origin of the strains.