Resistance Evaluation And Molecular Identification Of Hainan Common Wild Rice(Oryza Rufipogon Griff.) To Bacterial Blight

Rice bacterial blight(BB)is a worldwide disease caused by Xanthomonas oryzae pv.oryezae(Xoo),which has caused serious losses on rice production in southern China.Excavation and utilization of broad-spectrum lasting resistance genes to rice breeding has been considered as the most economical and effective strategy to control the disease.Therefore,it is of vital importance to choose the materials containing elite resistance genes.The common wild rice(Oryza rufipogon Griff.),which is wildly distributed in Hainan island,rich in resistance genes.Combing with Marker Assisted Selection detect gene composition of common wild rice,it is so important to identify common wild rice germplasm resistance to bacterial blight,and provide a theoretical for rational utilization of excellent common wild rice germplasm.In this study,52 common wild rice populations from various regions of Hainan and seven rice materials containing a single resistance gene were identified resistance to bacterial blight,52 common wild rice were analyzed with seven markers which tightly linked to the resistance gene cloned.The main findings are as follows:(1)Four bacterial blight strains were used to identify 52 common wild rices from Hainan Province,most of them showed good resistance to bacterial blight,and 26(50%)common wild rice showed resistance to four strains,only YDZ03 common wild rice showed susceptible and YDZ01 resistant to P6.(2)The two methods of CTAB and SDS were used for extracting plant DNA in this experiment,and it can be concluded that the SDS extracting method is more suitable for the DNA extraction of common wild rice duo to the DNA obtained by means of SDS was with high purity and good quality.(3)Combined with molecular markers which tightly linked to the resistance gene cloned to analyze 52 common wild rice,the results showed that the most of the common wild rice contain 2-3 known resistance genes except for YDF05,YWN03,YWN09 and YWN10.Nevertheless,YDF05 and YWN09 still have resistance to bacterial blight,which implies some other disease resistance genes should be contained in these two common wild rice.(4)The IRBB series(containing a single resistance gene)and the rice variety IR24(susceptible to BB)were identified by the bacterial blight strains,the IRBB series showed different resistance to the bacterial blight,in which the IRBB 13 and IRBB21 were resistant to all four strains,the IRBB1 and IRBB3 only resistant to P6 and P2.Whereas the IRBB5 was susceptible to P4 and P6,and the IRBB27 only susceptible to P6.