Studies On Breeding Of Small Chrysanthemum

Eleven introduced cultivars, 11 wild species and 20 cut flower cultivars of chrysanthemum (Chrysanthemum L.) involved in this experiment. A plenty of hybrid lines of small chrysanthemum with cold hardiness, disease resistance and good fancy points were gradually selected in natural hybridization with multiple male parents and treatment with high-voltage electrostatic field. The results are as follows:1. High-voltage electrostatic field with 166.67 ~200kv/m intensity has the optimum treatment effect on most of the hybrid seeds of small chrysanthemum. The mean germination percentage of hybrid seeds treated by high-voltage electrostatic field was 12.08% higher than that of control; the mean seedling survival rate was 9.52% higher.2. The variations of flower color were increased evidently by treatment of high-voltage electrostatic field. The flower color variation types in the treated and control groups were 85 and 42 respectively, flower variation rate of treated group was 97.67% more than that of control. Flower color variation indexes of different cultivars of small chrysanthemum were all increased but in different levels.3. For the natural hybrid lines treated by high-voltage electrostatic field, their disease resistance was increased, their flowering period was prolonged, and their flower size was more abundant.4. The selection criterion for superior hybrid lines of small chrysanthemum was established according to method of gradually eliminating less-desirable types. 98 plant lines with better variation characteristics were primarily selected from 5677 seedlings of hybrid lines obtained by the natural hybridization. And 16 superior hybrid lines of small chrysanthemum obtained by further selection for a period of one more year,5. The results of tissue culture from tubular corolla of multi-head small chrysanthemum shown that MS medium is the proper medium for micropropagation of small chrysanthemum.