Research On Tissue Culture Technology And Vitrification's Prevention Measure For Dendrobium

Dendrobium is a slow growing, low reproductive capacity itself orchid epiphytes, only rely on their own green leaves for photosynthesis. Because of different insect pollination, pollination generally poor results of little,Dendrobium from pollination to fruit maturity takes about 6 months. Under natural conditions, seed germination due to lack of nutrients required to coexist with the fungus, for the supply of nutrients to complete germination, the germination rate is very low. Dendrobium medicinal history of thousand years, but artificial cultivation of Dendrobium candidum in China only 30 years of history, although a few units have achieved large-scale cultivation now at Zhejiang and Yunnan, but production still can not meet the market demand, and higher production costs. Dendrobium direct collection of wild plants still very high proportion in the last century 80 to 90 years, the demand of Dendrobium officinale far beyond the resource capacity, this destructive way, difficult to achieve sustainable, so increasingly depleted resources of Dendrobium officinale. The only way to resolve the contradiction between demand and resources is artificial cultivation of tissue culture technology.In this study, seeds of Dendrobium were used as explants to establish a rapid micropropagation technique system in Dendrobium, and especially to find out some effective measures to control the vitrification. The results were as follows:1. The best option of means and time of disinfection:Through treating with 0.1% mercuric chloride, the germination·rate of Dendrobium will become high and the pollution rate will become low. After a short time of mercuric chloride treatment, it not only reduces the pollution rate, but also avoids the potential hazards of seed mercuric chloride.2.The best option of explants:Seeds were the best explants considering the rate of callusogenesis.3.The best initiation medium was MS+IBA0.5mg L-1+6-BA2.5mg L-4.The best medium for multiplication was MS+NAA1.5mg L-1+6-BA1.5 mg L-1+5% banana liquid extraction.5.The best medium for the rooting of shoot was MS+NAA1.5mg L-1+6-BA1.0 mg L-16.For transplanting of plantlets, the best medium was sawdust and perlite, the best time was May-July.7.Methods to control vitrification:Under the conditions of increasing the concentration of carbon dioxide or 60～80μmol·m-2·s-1 illumination, it can effectively prevent Dendrobium occurrence of vitrification and get the divert normal plants.