国际野生稻资源稻瘟病抗性鉴定与优异种质筛选OA

Rice blast,caused by Magnaporthe oryzae,is one of the most destructive diseases threatening rice production.Breeding and deploying resistant cultivars is a cost-effective and environmentally sustainable strategy for disease control.However,the frequent breakdown of resistance and the narrow genetic base of resistance genes remain major constraints,highlighting the need to identify new resistant germplasm.Wild rice,as a close relative of cultivated rice,harbors abundant genetic diversity shaped by natural selection and represents an important reservoir for novel blast resistance genes.Nevertheless,large-scale evaluation of blast resistance in international wild rice resources,especially those from Myanmar and Sri Lanka,remains limited.In this study,155 wild rice accessions from China and abroad were evaluated using a detached-leaf puncture inoculation assay against a mixed inoculum comprising 16 M.oryzae physiological races from Sichuan.The tested accessions showed substantial variation in blast resistance.In total,103 accessions were classified as resistant(R)or moderately resistant(MR),accounting for 66.4％of all accessions,including 76 R(49.0％)and 27 MR(17.4％).Among accessions from different origins,the proportion of R accessions from Myanmar and Sri Lanka was 57.7％and 55.6％,respectively,slightly higher than that from China(40.0％from Hainan and 50.0％from Guangxi),and they exhibited relatively lower disease indices.Notably,the resistance frequency(R+MR)of O.nivara from Sri Lanka reached 90.0％,while most accessions from Myanmar were classified as resistant.These results indicate that wild rice accessions from Myanmar and Sri Lanka exhibited higher proportions of resistant and lower proportions of susceptible accessions.In particular.O.nivara from Sri Lanka holds great promise for mining broad-spectrum blast resistance genes and selecting resistant donors.This study provides valuable germplasm resources for broadening the genetic basis of blast resistance in rice breeding.