Abstract:

Based on the 13 morphological traits of 950 accessions of spray cut chrysanthemum （Chrysanthemum morifolium）including eight ligulate flower color groups preserved by China Chrysanthemum Germplasm Resources Conservation Center,cluster analysis was performed by systematic cluster method. Based on two genetic distances,four clustering methods and five overall sampling scales,40 candidate core collections were constructed,and thereafter four evaluation indexes were used to compare the quality of the candidate core collections and an optimal scheme was selected to construct primary core collection. Six characteristic values and five evaluation parameters were used to comprehensively evaluate the effectiveness and representativeness of core collections,and finally an optimum core collection constructed by standardized Euclidean distance,Ward's method and 10% overall sampling ratio was observed showing superior comprehensive performance. The derived primary core collection containing 95 spray cut chrysanthemums could fully represent the genetic diversity of the original collection under the condition of less redundancy,and thus should be effective and of high quality.

Key words: chrysanthemum, cut flower, core collection, morphological trait, construction strategy