1018份普通野生稻种质资源稻瘟病抗性鉴定与评价OA

Wild rice(Oryza rufipogon Griff.)harbors extensive genetic diversity and superior environmental adaptability,serving as an invaluable genetic materials for the genetic improvement of cultivated rice.Rice blast,caused by Magnaporthe oryzae,is categorized as a Class Ⅰ agricultural pest by the Ministry of Agriculture and Rural Affairs of the People's Republic of China.Exploiting elite resistance resources to develop broad-spectrum resistant cultivars is considered the most cost-effective and sustainable management strategy.In this study,1018 O.rufipogon accessions collected from Guangdong,Hainan,and Guangxi of China were evaluated for resistance to rice blast using 42 predominant physiological races of M.oryzae from Sichuan,Chongqing,Guizhou,Jiangxi,Yunnan,Hubei,and Jiangsu.When challenged with the Southwest mixed isolates(from Sichuan,Guizhou,and Chongqing),88 accessions were resistant(R),34 moderately resistant(MR),124 moderately susceptible(MS),and 772 susceptible(S).Among the 122 accessions showing resistance(R and MR)to the southwest mixture,69(56.6％)were resistant to isolate B27 from Hubei,81(66.4％)to the Jiangxi mixed isolate,111(91.0％)to isolate Q12 from Yunnan,and 113(92.6％)to isolate C62 from Jiangsu.Sequential screening identified 59 accessions with broad-spectrum resistance(R and MR)to all 42 predominant isolates,including 45 from Guangdong,five from Guangxi,and nine from Hainan.Notably,the frequency of broad-spectrum resistance in Hainan(22.0％)was significantly higher than in that Guangdong(5.1％)and Guangxi(5.4％).These broad-spectrum-resistant wild rice germplasm resources represent a pivotal germplasm reservoir that underpins future investigations into rice blast resistance and accelerates the breeding of resilient cultivars.