Identification Of Resistance To Bacterial Blight And Detection Of Resistance Gene Xa5 And Xa27 In 153 Commercial Rice Varieties

Bacterial blight,caused by Xanthomonas oryzae pv.oryzae(Xoo),is a serious disease in rice production worldwide.It is of great significance to identify the resistance of rice varieties to bacterial blight and the composition of disease resistance genes,so as to combine with the local dominant species,rationally arrange the varieties,and to avoid the outbreak of bacterial blight.In this study,the resistance of 153 rice varieties to nine bacterial blight races were identified and the resistance gene xa5 and Xa27 among these 153 varieties were detected.(1)In this study,153 varieties collected from 14 provinces were inoculated with 9 races of bacterial blight in 2015 and 2016.The results showed that:The provinces of Heilongjiang and Jilin(Northeast China)are lack of the resistant varieties to local dominant races R9,and most of the varieties have narrow resistant spectrum;The provinces of Anhui,Jiangsu and Zhejiang(East China)all have resistant varieties to their dominant races R5 and R8;In,the provinces of Guangdong,Fujian and Guangxi(Southern China)all have resistant varieties to their dominant races R5 and R8.However,Guangdong has only one resistant variety to R8,and Fujian has one and two resistant varieties to R5 and R8,respectively;The provinces of Hunan,Hubei and Jiangxi(Central China)all have resistant varieties to R4 and R5.However,Hunan has only one and two resistant varieties to R4 and R5,respectively,and all of these three provinces are lack of resistant varieties to R2,R8 and R9.The provinces of Sichuan,Yunnan and Guizhou(Southwest China)all have resistant varieties to their dominant races R5,but only Guizhou has one resistant variety to dominant species R9.(2)dCAPS and InDel markers were designed according to the sequence differences of xa5 and Xa27 genes between resistant and susceptible varieties.The results show that no recessive homozygous of xa5 gene was detected in all 153 varieties,and the dominant homozygous of Xa27 genes were only detected in Liangyou8106 and Tianfengyou084.The results providethe basis for the layout of different rice growing regions and breeding for resistance to bacterial blight.