Identification and evaluation of Guangxi wild rice (Oryza rufipogon Griff) resources with wide spectrum resistance to bacterial blight

【Objective】The resistance of 1498 accessions of Guangxi wild rice(Oryza rufipogon Griff) to bacterial blight(BB) was evaluated in order to provide materials for breeding rice varieties with wide spectrum of resistance to BB.【Method】The dominant type Ⅳ strain in indica rice planting regions of South China was used for identifying 1498 accessions of Guangxi wild rice.The resistances of selected accessions were further identified by using several other BB races.In addition,the correlation between disease resistance of Guangxi wild rice population groups and their genetic diversity was also analyzed.【Result】By using type Ⅳ strain,70 accessions wild rice with stable resistance to BB were obtained.Through further identification of 60 accessions with 7 dominant strains of Guangxi(Ⅰ~Ⅶ type strain),43,50,45,58,52,46 and 46 accessions were found to be moderate resistant,resistant,or high resistant to Ⅰ~Ⅶ type strain,respectively.Two accessions,viz.,RB11 and RB19,were resistant to all 7 tested strains.Three accessions,viz.,RB5,RB7 and RB31,presented high resistance to the Ⅶ,Ⅴ and Ⅴtype strain,respectively.The resistant material frequency of Guangxi wild rice was not significantly correlated with genetic diversity index of population group,but negatively correlated with the geographic latitude of O.rufipogon population groups.【Conclusion】Some wild rice accessions with wide spectrum resistance and high resistance to BB were obtained through resistance identification,and they could be used for BB resistant parents on breeding rice varieties.