Study on Phenotypic Diversity of Related Characters in Flower of Rosa hybrida

In order to study the genetic diversity of floral traits of Rosa hybrida, 9 flower characters were selected from 73 R. hybrida resources for correlation analysis, cluster analysis, principal component analysis and comprehensive evaluation. The results showed that the phenotypic traits of R. hybrida germplasm resources have a high degree of variation, diverse types, and rich genetic diversity. Among of them, the average coefficient of variation of the 6 quantitative traits is 64.00%, and the coefficient of variation of the number of flower heads is the largest; the diversity of quantitative description traits is greater than the diversity of qualitative description traits, and the diversity of petal numbers is the largest. Correlation analysis showed that there were 15 pairs of extremely significant related traits in 73 R. hybrida varieties. Cluster analysis showed that 73 rose varieties can be divided into 3 groups at the Euclidean distance of 10. Accroding to principal component analysis, the first three principal components can show most of the information of 9 flower traits, with a cumulative contribution rate of 71.19%. And the contribution rate of the first principal component was the largest, which is 44.50%. Among the 73 R. hybrida resources, R. hybrida 'Hiogi' has the highest overall score, and R. hybrida 'multiflora inermis' has the lowest overall score. Combined with stepwise regression analysis, the flower diameter, petal length, petal width, petal area and number of flower heads can be selected as the comprehensive evaluation indexes for the flower traits of R. hybrida.