| In this paper, obtaining aseptic plant by means of aseptic seeding, using parts of the plant stems as explants, We studied on the effect of factors which affected the in vitro culture and in vitro flowering of S. davidiana var. undulata, such as plant hormones, carbon sources, basic medium, active carbon, etc at the stage of proliferation culture, rooting culture and flower induction. As a result, the best mediums of every stage were screened out, tissue culture system for S. davidiana var. undulata was established, and flower bud induction was explorated. In addition, the landscape application of S.davidiana var. undulata was preliminary discussed. In this study, it can provide the efficient breeding to the the oretical and experimental basis for wild plants resources.The main results as following:1 Establishment of rapid propagation system. After disinfection treatment with 0.1 % HgCl2, disinfection time 15 min, survival rate of mature embryos was 90 %.Adding 6-BA(0.52.0 mg·L-1) was beneficial to the adventitious buds production, 1.0 mg·L-1 was able to achieve the best effect, and growth coefficient was 3.94. Adding TDZ(0.050.20 mg·L-1) was beneficial to the adventitious buds production, 0.2 mg·L-1 was able to achieve the best effect. Though growth coefficient was 3.94, the plant growth status of TDZ was obviously inferior to the 6-BA. Sucrose was the best carbon source of the proliferation medium, and the best concentration was 30g·L-1. The optimal medium for propagation were 1/2MS + 0.10 mg·L-1NAA and 1/2MS + 0.20 mg·L-1IAA, rooting rate were 88.33 %,86.67 % respectively, average root number were 10.28,7.81, and average root length were 0.32 cm,0.83 cm after 30 days. Besides, MS + 0.20 mg·L-1NAA and 1/2MS + 0.10 mg·L-1IAA can be selected. There was obvious promotion to average root length of S.davidiana var. undulata by adding active carbon into medium. The best time of hardening plantlets was 10d, transplanted in the artificial mixture with the ratio of perlite︰vermiculite︰peat (1︰1︰1), and survival rate was the highest.2 Flower bud induction exploration. S. davidiana var. undulata can bloom in three years under natural conditions, but it can bloom after three months by means of aseptic seeding or one month by sterile materials induced. As a result, different types and concentrations of cytokinins on flower induction played an important role, the concentration which was too be high or too be low was not beneficial to the flower bud induction, 6-BA1.0 mg·L-1 and TDZ2.0 mg·L-1 were the best, and flower bud induction rates were 10.0% and 5.0%, while, the common use of cytokinin and auxin was not conducive to the flower bud induction. Carbon sources also played an important role on the flower bud induction, Sucrose was the best carbon source, and the best concentration was 30 g·L-1 compared with other concentrations, flower bud induction rate was 10.0%. In addition, the induction of different nitrogen to phosphorus ratio had no effect on the flower bud.3 Landscape application discussion. The leaves,flower and fruit of S. davidiana var. undulata have high ornamental value, which could be developed as ground cover plant; colorful; plant hedge, lower fence, and fruit fence; molding plant and so on. |
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