| The chrysanthemum[Chrysanthemum grandiflorum(Ramat.)Kitamura], an important cut and pot flower world wide, has high ornamental and economic value. It is important to establish a synthetic system for assessing the quality of different varieties, and to analysis the correlation between different characters for offering technological support in selecting, introducing, and cross breeding of cut chrysanthemum. In this paper, a synthetic system was established for standard and spray cut chrysanthemum respectively, and 58 standard cut chrysanthemum varieties,160 spray cut chrysanthemum varieties were estimated. Also, flower diameter with other quantitative characters in standard cut chrysanthemum was studied by correlation and path analysis, genetic variability patterns and the correlation between 14 quantitative characters of spray cut chrysanthemum was analyzed. The main findings are as follows:(1)A synthetic system was established for standard cut chrysanthemum by means of expert consultation, analytic hiberarchy process and K-Means cluster method. The factors affecting the quality of standard cut chrysanthemum was analyzed, and 13 factors were selected. The weight of the 13 factors was quantitatively evaluated by analytic hierarchy process. Flower diameter, flower color and ray flower number had the most important effect, and the weight was 0.113,0.106,0.106 respectively.58 varieties of standard cut chrysanthemum were then clustered into 3 grades by K-Means cluster method, and 14 varieties graded well were selected.(2)A synthetic system was established for spray cut chrysanthemum, and the factors affecting the quality of pray cut chrysanthemum were analyzed.11 factors from all of them were selected. Plant character, flower color and branch length had the most important effect, and weighting 0.228.0.150,0.132 respectively.160 spray cut chrysanthemum varieties were then clustered into 4 grades by K-Means cluster method, and 41 varieties graded well were selected.(3) The flower diameter and 11 quantitative traits of 27 cultivars of standard cut chrysanthemum were investigated. Analysis of genetic correlation, correlative heritability and path analysis were conducted. The results indicated:heritability of broad sense was relatively high for the 12 characters, being all higher than 70%. Flower diameter was in highly significant positive correlation with the length of the first round ray florets and the length of the second round ray florets, and in significant positive correlation with the width of the second round ray florets. Correlative heritability of the length of the first round ray florets and the length of the second round ray florets related to the flower diameter were higher, respectively, and were close to heritability of the flower diameter. The efficiency of correlation selection of these two traits would not be much lower than direct selection of the flower diameter. It is, therefore, concluded that selection should be made for longer and greater number of ray florets, lesser number of tubular disk florets and higher plant height in selecting excellent standard cut chrysanthemum varieties.(4) Analysis of extent and pattern of diversity, heritability in broad sense and genetic advance were conducted with 14 quantitative characters of spray cut chrysanthemum. The phenotypic coefficient of variability of 14 quantitative characters ranged from 15.86%for stem diameter to 74.11%for number of ray floret. Generally, the phenotypic coefficient of variability was a little higher than genotypic coefficient of variability for each trait. All quantitative characters exhibited considerably high heritability in broad sense (>86.80%). The highest h2 was number of ray floret (98.81%), and there was a high genetic advance of 148.49%for it, this indicated the presence of additive gene action, which suggested that direct selection was suitable for improvement this tratit. A correlation analysis revealed that a broad correlation existed among the traits investigated. |
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