186份寒地粳稻种质资源数量性状遗传多样性分析与评价OA

To systematically evaluate the genetic diver-sity of quantitative traits in cold-region japonica rice germplasm resources and clarify trait relationships to provide theoretical basis for excellent germplasm resource selection and parental combination,a total of 186 cold-region japonica rice germplasm resources were analyzed for 19 quantitative traits using quantitative genetics and multivariate statistical methods.The results indicated that all 19 traits exhibited abundant genetic variation,with coefficient of variation(CV)ranging from 1.24％to 75.73％.Chalky grain rate showed the highest CV,while brown rice rate showed the lowest CV.Correlation analysis revealed that plant height was significantly or extremely significantly correlated with the other 18 traits,demonstrating strong pleiotropy.Yield was extremely significantly positively correlated with panicle number,panicle length,growth number per panicle and taste value.Taste value was extremely significantly positively correlated with head rice rate and amylose starch content,but was extremely significantly negatively correlated with chalky grain rate and chalkiness degree.Cluster analysis classified the 186 rice germplasm resources into four groups:group Ⅰ had the highest proportion and exhibited the highest protein content and the lowest taste value;group Ⅱ showed advantages in panicle number,seed setting rate and 1 000-grain weight;group Ⅲ displayed the lowest proportion and the highest mean values of plant height,panicle length,grain number per panicle,yield,taste value and grain shape traits(grain length-width ratio,grain length,milled rice length-width ratio,milled rice length);group Ⅳ had the highest head rice rate,chalky grain rate and chalkiness degree.Principal compo-nent analysis extracted six principal components with cumulative contribution of 85.233％,representing grain shape,cooking and eating quality,milling quality,appearance quality,panicle structure and grain weight,respectively.Ten excellent gennplasm resource including Zhongke 804,Zhongkefa 5 and Dongfu 105 were identified through comprehensive evaluation.This study provides theoretical foundation and germplasm support for breeding superior japonica rice varieties in cold-region rice area of China,and has important reference value for promoting the breeding of new japonica rice varieties.