Studies On Genetic Diversity And Phylogenetic Relationship Of Chrysanthemum Germplasm Resource Using AFLP Technique

Chrysanthemum (Dendranthema×grandiflorum) originated from China and the germplasm resource is very abundant. In a long-term course of cultivation and domestication, it has formed thousands of cultivars whose flower color, flower style, body style and leave style were different. But the work of breeding was greatly restrict for lack of an in-depth and systems study of its genetic background and phylogenetic relationship. In this study, the genetic diversity and phylogenetic relationship of chrysanthemum were systemically analyzed using AFLP technique, which provide theoretical foundation for its origin, evolution and auxiliary selective breeding.The main research results obtained are as followings:1. The genome of chrysanthemum is great, and the content of amylase and phenolic compound is high, which influences frequently the yield and quality of genome DNA when being extracted or being analyzed with AFLP. The result showed that the modified method found in this paper could effectively eliminate the affections of the secondary materials to extracted genome DNA from chrysanthemum leaves, and which be suitable for AFLP analysis.2. Six pairs of primers E37/M35, E48/M60, E32/M50, E41/M38, E48/M64, E37/M50 are chosen from 64 pair of primers with AFLP analysis, and the clear polymorphic fingerprints were obtained which showed that it is feasible for using these primers in chrysanthemum AFLP analysis. Six pairs of primer combinations generated 244 bands in total, in which 178 bands were polymorphic and the average percentage of polymorphic bands was 72.95%. These showed that the genetic diversity of Chrysanthemum is abundant.3. Cluster analysis by UPGMA showed that 65 chrysanthemum cultivars could be divided into four groups where the genetic distance was 0.68. It was consistent with the morphologic classification based on petal type on the whole. Their origin was correlated with the cluster results to a certain extent. Of the 65 cultivars, 6 occident cultivars had close genetic relationships. But the genetic relationships between cultivars of Occident and Chinese or Japanese and Chinese were also close. The clustering result showed no clear pertinence with the flower color.