Mining and Preliminary Mapping of Rice Resistance Genes Against Bacterial Leaf Streak
Bacterial leaf streak(BLS),caused by Xanthomonas oryzae pv.oryzicola(Xoc),is one of the most important diseases of rice,which is now highly prevalent in rice-growing regions of China,especially in Southern China(including Jiangsu,Zhejiang,Fujian,and Guangdong).Planting resistant varieties is considered as the best approach to control BLS.However,no resistant cultivars are available owing to limited genetic resources for BLS resistance.Two highly BLS-resistant materials(M1 and D1)have been discovered in our research by screening germplasm against BLS via syringe inoculation.Multi-strain inoculation showed that M1 had the characteristics of race-nonspecific broad-spectrum resistance(RNS BSR).The genetic population analysis showed that the cultivated rice M1 harbored a single dominant new gene Xo-3 of resistance to BLS.Through BSA-seq and association analysis,Xo-3 was initially mapped in a candidate region on chromosome 2.The mining of germplasm resources of BLS-resistant and the analysis of the genetic basis of its resistance will help our understanding of the interaction mechanism between rice and Xoc,so as to cultivate new varieties of BLS-resistant rice and development scientific strategies in controlling BLS.