Studies On Rapid Reproduction And Organ Formation Of Chiritopsis Repanda Var. Guilinensis

Gesneriaceae has many varieties, including150genus and3700species in the world. And there are56genus and463species in China, which belong to Cyrtandroideae. Chiritopsis repanda var. guilinensis is one of the most rare species and endemic in Guangxi, which grew poorly in the shady side of hills and the limestone substrate near the cave, or in the dry gap between the drought stone walls, damaged by diseases and insects, according to a rough survey in Guilin. It is necessary to build a technology system of artificial breeding and protection to get the seeds and plants in quantity for the reducing population of Chiritopsis repanda var. guilinensis affected by human activities significantly.This study mainly researched cutting propagation, rapid reproduction and organ formation anatomy of the Chiritopsis repanda var. Guilinensis, using its leaves as explants. The results were as follows:1. Rapid reproduction system of Chiritopsis repanda var. Guilinensis was set up. HgCl2was selected as the surface disinfectant. It was optimum to disinfect the leaves of wilding with0.1%HgCl2for6min, and the leaves in pot culture with0.1%HgCl2for4min. Compared with the leaves of wild plants and potted plants, and the petiole, stem and leaves of test-tube plantlets, the leaves of test-tube plantlets was the optimal explants for adventitious buds induction, with the highest coefficient of differentiation. The optimum hormone for adventitious buds induction was6-BA and NAA, using tue plantlets as explants. The optimum medium for adventitious buds induction was MS+6-BA0.1mg/L+NAA mg/L+sucrose30g/L+arga7g/L, the enhancement factor was23.79.1/2MS+sucrose30g/L+Ac5g/L+arga7g/L were suitable to promote the growth of root, with the rooting rate reached100%. The humus soil was used as medium when transplanting, and the survival rate was90%for Chiritopsis repanda var. guilinensis, reached highest.2. The histological examination of adventitious buds indicated that there were two ways to produce them. One was directly from epidermal cells and the following several layers of cells in vitro leaves. And the other was indirectly from primordium, which was differentiated from callus. 3. The primordium of adventitious root originated in the cambial cells in the type of the induced radication.4. The study on cutting propagation revealed that the thick river sand for the matrix gave the best result, which was using the whole leaf as materal but without petiole.