Genetic diversity analysis of fruit-related traits in cucumber germplasm resource
To understand the genetic diversity of cucumber fruit traits and optimize breeding strategies,genetic diversity analysis,correlation analysis,principal component analysis and cluster analysis were performed for 13 fruit agronomic traits of 221 germplasm resources.The results showed that the average genetic diversity index of 221 cucumber germ-plasm resources was 1.392,with the average coefficient of variation of 30.78%.Correlation analysis showed that except the size of fruit tumor,the other 12 traits had high correlation.Principal component analysis showed that the cumulative contribution rate of the four principal components(PC1-PC4)was 68.82%,which contained most of the information of cucumber fruit traits.Cluster analysis was conducted on germplasm resources using phenotypic traits and molecular mark-ers.The results showed that the phenotypic traits of 221 germplasm resources were divided into 5 categories when the Eu-clidean distance was 0.003,and each category contained 90,65,9,38 and 19 germplasm resources,respectively.When the Euclidean distance was 1.400,the molecular markers of 221 germplasm resources were divided into 5 categories,in-cluding 35,70,45,54 and 17 germplasm resources,respectively.The comparison between phenotype data and molecular marker clustering results showed that there was a certain degree of agreement between them.The results have laid a foun-dation for the selection of excellent breeding parents and provided a reference for the subsequent work.