Resistance to rice blast of the primary core collection of Chinese rice germplasm ( including 203 accessions) was evaluated.Among the 203 rice accessions,41.38％ and 78.82％ were resistant to leaf blast and panicle blast,respectively.Twenty-eight varieties ( 13.79％ ) showed resistance to at least 70％races of Magnaporthe grisea (Hebert) Barr,with 66.50％ of the tested varieties resistant to 20％ -70％races of the pathogen.According to the correlation analysis, resistance spectrum of the varieties in seedling stage was significantly correlated with leaf blast resistance at the 0.01 probability level (r = -0.362 4,P ＜ 0.000 1 ) but not with panicle blast resistance.Leaf blast resistance was aslo not significantly correlated with panicle blast resistance.According to the results of clustering analysis ,japonica rice varieties from the primary core collection could be classified into seven groups.Fifteen varieties including Xugunuo,fallen assigned 7 groups.The group 3 were resistant to the races of C, D, E and F with resistance spectrums from 68.8％ to 87.5％.For indica rice,twenty-six vareties belonging to group five( six groups in total)were resistant to races of E,F and G with resistance spectrums from 50.0％ to 87.5％.%对203份中国稻种资源初级核心种质对稻瘟病的抗性进行了评价.在这203份中国稻种资源初级核心种质中,抗时瘟和穗瘟的品种分别占41.38%和78.82%.对供试的16个稻瘟病菌系抗谱在70%以上的品种有28个(13.79%),66.50%的品种抗谱在20%-70%之间.相关分析结果表明,供试品种苗期抗谱与成株期叶瘟抗级相关性极显著(r-0.362 4,P＜0.0001),而与穗颈瘟抗级的相关不显著.同时,供试品种叶瘟与穗颈瘟的抗级间的相关性也不显著.根据聚类分析结果,中国稻种资源初级核心种质的粳稻对稻瘟病的抗性分成7类,其中,第3类包括须谷糯等15个品种,抗C、D、E、F群生理小种,抗谱68.8%～87.5%,抗叶瘟和穗颈瘟.而籼稻品种可分为6类,其中,第5类包括桂朝2号等26个品种,高抗E、F、G各群菌株,抗谱为50.0%～87.5%,抗穗颈瘟.以上材料可作为水稻抗稻瘟病育种优先利用的种质资源.
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