Analysis of Phenotypic Genetic Diversity of Various Phalaenopsis Varieties

In this study, 34 phenotypic traits involving leaves, floriferous shoot and floral organs of 72 Phalaenopsis germplasm resources were measured and evaluated by using means of phenotypic diversity analysis, principal component analysis and cluster analysis, the genetic diversity of germplasm phenotypic traits was explored. The results showed that the majority traits in 72 Phalaenopsis varieties had exhibited high degree of variation and rich types, the variation of quantitative traits was 16.39%–157.36%, and the Shannon-Wiener diversity index of qualitative traits was 0.38–1.32, the coefficient of variation of quantitative traits for leaf-related traits was small and stable, but the level of diversity of quality traits for leaf-related traits was relatively high. R-type cluster analysis divided the 34 traits into 3 clusters, with cluster I containing phenotypic traits of flower and leaf, indicating a close relationship between the phenotypes of flower and leaf, and clusters II and III only contained inflorescence length, longest leaf length, plant size and peduncle length, it is indicated that these 4 phenotypic traits including inflorescence length have the relationship for independent evolutionary. Q-clustering analysis divided the species of Phalaenopsis into 4 primary groups, group II could be subdivided into 7 subgroups. The germplasm of subgroups II−1 and II−2 could provide parental choices for large-flowered and medium-flowered breeding, the germplasm of subgroups II−3, II−4, II−5 and II−7 could provide parental choices for small-flowered breeding, the germplasm of subgroup II−4 could provide parental choices for fragrant-flowered Phalaenopsis breeding, and the genetic distances of 'JB5342', 'JB5184', 'JB5541', 'JB3697', 'Anna' and 'JB5725' were far with the most samples, and they could be selected as the significant hybrid parents. Principal component analysis showed that flower width, petal length, petal width, sepal length, flower length, and sepal width had high absolute value of eigenvector and were the main factors causing the phenotypic variation of Phalaenopsis.