Research On Key Techniques Of Seedling Rapid Propagation And Cultivation Of Demdrobium Officinale

Demdrobium officinale Kimura et Migo, a perennial herbaceous plant of Demdrobium genus, orchid family, is a famous traditional rare medicinal herbs. It possesses the functions such as regulating blood sugar level, anti-tumor, nourishing body and anti-aging etc. And it’s obvious curative effect on the digestive, respiratory, cardiowascular system and eye diseases. In this paper, variety of Demdrobium officinale named Yun-nan-ruan-jiao was taken as experimental material. Technology of tissue culture and rapid propagation were established with the mature but not lobed capsules which getting from artificial pollination as explants. Meanwhile, the key technology of cultivation was studied through the research of cultivation environment and pest control technology. The main results are summarized as follows:1. Tissue culture and rapid propagation of seedlings industrialization technique of Dendrobium officinale:(1) Efficient rapid propagation system was established by aseptic sowing and tissue culture with not-dehiscent and growth190d capsules. Seed germination culture medium was MS+NAA0.2mg/L+Banana mud7%+AC1.0g/L. The germination rate was90%and the propagation coefficient was15after cultivating60-80d.(2) The protocorm proliferation and differentiation culture medium was MS+6-BA0.5mg/L+NAA0.2mg/L+Banana mud7%+AC1.0g/L. The differentiation rate and proliferation coefficient were80%and6.0/60d during2-4generation, and90%and4.0/60d during5-7generation of subculture. The total number of subculture should be less than10generations.(3) The rooting culture medium was1/2MS+NAA0.1-0.8mg/L+AgNO30.1-0.6mg/L+Banana mud7%+AC1.0g/L. The rooting rate was100%after cultivating60d. In this medium, the seedling was strong and had a good stress tolerance so the period of transplantation time could extended more than50d.(4) Two types variation of tissue-culture seedlings of Dendrobium officinale was found and the factors which induced the two types variation were studied respectively. While the avoiding measures were summarized and used for guiding seedling production. As a result that the huge loss of property would be avoided during seedling production.(5) After acclimatized in greenhouse for7-20d, the tissue-culture container seedlings of Dendrobium officinale were transplanted on seedbed with broken and germfree pine bark in greenhouse during spring and autumn. The survival rate was95%。(6) According to this technology, one bottle aseptic sowing material of Dendrobium officinale can be multiplied7900-3,600,000ones, and propagate400,000-18,000,000seedlings in a production cycle in theory.2. Cultivation technique of Dendrobium officinale(1) Da Yuan forest farm in Yangshuo County of Guang Xi was suited to be a green planting base of Dendrobium officinale according to the quality testing results of the ambient air, soil and irrigation water.(2) The transplanting time of tissue culture plantlets of Dendrobium officinale:May to June and October to November were the suitable days for the tissue culture plantlets of Dendrobium officinale transplanting in a year in GuiLin Region. The survival rate were both over90%and the former was better than the latter.(3) The yield accumulation and quality formation process of Dendrobium officinale: The tiller number increased to5times while the weight increased more than40times after transplanting3year later. The polysaccharide content accumulated to harvest standard after transplanting18months. And the content of polysaccharide would stabilize in a high level (about30%) after transplanting two years later.(4) The optimal light environment of Dendrobium officinale plantation:Light transmittance55%was beneficial to yield formation and polysaccharide accumulation of Dendrobium officinale; and made the plant had a high net photosynthetic rate and high content of chlorophyll a and b. Therefore, Light transmittance55%was the optimal light environment for Dendrobium officinale plantation.(5) The main diseases and pests of Dendrobium officinale and its control:There were14kinds of diseases and insect pests in plantation of Dendrobium officinale, and six of them harm serious. In this paper, the occurrence regularity of four Serious harm types including Bacterial Soft Rot, Anthracnose, Black Spot, Snails and slugs were studied and the corresponding prevention suggestions were provided.