Study On Regeneration System Of Chrysanthemum Nankingense

Chrysanthemum(Chrysanthemum morifolium) with high economic and ornamental vaule from China, is one of the four famous cut-flowers in the world. However, chrysanthemum has a complicated evolution history and various chromosome ploidies, which cause great barriers to study its important ornamental characteristics with molecular method. Chrysanthemum nankingense (Asteraceae) belongs to diploid and involves in the evolution of chrysanthemum, it will contribute to study the complicated biological phenomena in chrysanthemum as the model plant. Currently, there are less reports on regeneration system of C. nankingense.. Therefore, this study focused on regeneration of different organs and studied the plantlet rapid growth, which would provide basis for genetic transformation C. nankingense. The main results were as follows:1. Taking the leaves, stem epidermis, hypocotyls, seeds and flower organs as explants, respectively, various combinations of plant growth regulators were used to induce callus and adventitious buds to establish the regeneration system of C. nankingense. The results showed that explants and combinations of plant growth regulators had great effects on regeneration. For callus induced from leave and hypocotyls, it was hard to get adventitious buds. Taking flower buds as explants, the regeneration process cost the shortest time while the regeneration rate was maximum(66.5%), the optimal regeneration medium was MS+6-BA 2.0 mg·L-1+NAA 0.25 mg·L-1, further analysis revealed that regeneration rate of torus was 42.6%, of ray flower and tubular flower was 16.7% and 13.1%, respectively, while only a small amount of buds differentiated from ovary; and the adventitious buds originated from torus in flower bud by histological observation. For stem epidermis, the maximum regeneration rate was 28.4%, the optimal callus induction medium was MS+AC 2.0 g·L-1+IBA 1.0 mg·L-1+6-BA 0.1 mg·L-1, the optimal regeneration medium was MS+AC 2.0 g·L-1+TDZ 0.5 mg·L-1+NAA 0.1 mg·L-1. For seeds, the maximum regeneration rate was 19.8%, the optimal callus induction medium was MS+2,4-D 1.5 mg·L-1+6-BA 0.05 mg·L-1, the optimal regeneration medium was MS+6-BA 2.0 mg·L-1+NAA 0.05 mg·L-1.2. Taking the shoot apices of C. nankingense as explants, comparing different culture factors such as plant growth regulators, carbon sources, additives and culture time on rapid propagation of C. nankingense. The optimal multiplication medium was MS+6-BA 1.0 mg·L-1+NAA 0.1 mg·L-1+sucrose 20 g·L-1, and the multiplication time had better less than 6 weeks. The optimal rooting medium was 1/2MS+IBA 0.2 mg·L-1+sucrose 20 g·L-1. Adding banana slurry 20 g·L-1 in rooting medium was beneficial to rooting and accumulating dry matter, which enchanced the quality of plantlet.