Genetic Diversty of Different Original Peony Cultivars
|School||Nanjing Agricultural College|
|Course||Ornamental Plants and Horticulture|
|Keywords||Peony morphology diversity principal component analysis clusteranalysis ISSR genetic relationship|
The germplasm of Paeonia sect.Moutan was endemic to China. China is not only the distribution center of wild species of Sect.Moutan, but also has cultivated numerous cultivars of P. suffruticosa. The phylogenetic research work of Sect.Moutan was mainly concentrated in the taxonomy of species of Sect.Moutan and morphologic classification of cultivars by morphologic observation, sporo-pollen analysis, cytologic and molecular biologic technique. But few focused on the phylogenetic relationship and diversity about species of different origin expecialy with molecular phylogenetic techinology. This paper reported the relative research work by morphology and ISSR analysis. This experiment enrichied the molecule phylogenesis studies of Paeonia Suffriticosa, the dendrogram of descendibliy was obatined, which gave the foundation for the further research, using this relationship can provide predicitions for new cultivars breeding of tree peony and contribute it to the tree peony industry in China. The major results were as follows:1In this paper, forty-one morphological characters were investigated in93cultivars of Peony. The results showed that the morphological diversity was high among cultivars. Coefficient of variation based morphological traits ranged from14.30%to158.99%with the average of44.49%. The principal component analysis showed that the41characters were integrated into10principal components.10principal components represented59.97%of variance, containing majority information of all index. Further more, the first, third, fifth, sixth, seventh, eighth and ninth components can be combined into the first factor, representing for flower characters (stamen state, petaled anther color, petaled anther form, petal basal spot form, petal basal spot color, flower form, pedicel state, petaled pistil color, filament color, flower color, stigma color, flower across length, flower height, plant height). And the second, fourth and tenth components can be combined into the second factor, representing for leaf characters (leaf tip shape, length of fresh-branch, top-leaf top, compound leaf type, length of leaves, width of leaves, side-leaf form). The principal component analysis result supported cluster analysis result. Based on the morphological data, these cultivars of Peony were clustered into2groups. The first group was characterized by leaf faint, big flower across length, no petal basal spot, late florescence and pedicel upwards, most cultivars of which are foreign cultivars. The second group was characterized by no leaf faint and small flower across length, including foreign and Chinese cultivars, which can be classified by further clustering. Cluster analysis result showed that peony cultivars with different origin can be classified by morphological diversity analysis. Optional progeny were achieved by crossing from different country parents in breeding of Peony.2ISSR-PCR was used to detect the genetic diversity and relationship of these peony cultivars. ISSR fingerprinting amplified by19ISSR primers revealed a total number of188unambiguous bands, of which177ones were polymorphic and the polymorphism frequency was94.1%. As analyzed by POPGENE1.31, the average value of effective number of alleles, Nei’s gene diversity and Shannon’s information index were1.514,0.3085and0.4713, respectively. As analyzed by NTSYS, the similarity coefficient between cultivars ranged from0.3294to0.7744, the average value is0.5722. These peony cultivars were divided into2groups by UPGMA (unweighted pair group method with arithmetic average) based on similarity coefficient. The genetic relationship of these cultivars was related to their origin, flower form and flower colour. The results of the evaluations of genetic diversity in different original peony cultivars based on the two methods were similar.