Resources Conservation And Preliminary Study Of Endophytic Fungi Of D.officinale

In this paper, using Dendrobium officinale as materials, using stem segment as explant, establishing a culture medium system suitable for resources conservation and fast propagation. We selected optimal media and conditions for the tissue culture of Dendrobium officinale by testing and comparing various factors. To summarize the process of reduction callus into young plants and affecting factor in morphological terms. By means of physiological and biochemical indexes, the effects of different concentrations of germinium on the growth, protective enzyme systems and membrane systems in Dendrobium officinale were studied. Some fungi were obtained from the roots of Dendrobium officinale. We identitied some of which by rDNA ITS total sequence analysis. The results showed as follows:Established a new effective way of using stem segment as explant to conserve resources. 1/2MS media were suitable for cluster bud reduction. 1/2MS+6-BA2.0 mg/L+NAA0.2mg/L was better to reducing cluster bud than other media. Added 10% banana juice was suitable for plantlet rootage and strengthening.After root reduction, the cluster bud can be grow into complete plant, the breeding cycle were shortened greatly.The callus may develop into protocorm like bodies(PLBs) on the same medium. The division of protocorrm like bodies go through I type and II two period of stage , and the II type protocorm can form the adventive bud, the two types can give rise to complete plants. The size, part and physiological state of the explant affect the induction of the callus. The development of callus which gave rise to protocorm like bodies and adventive buds allowed a clonal mass propagation. This improves greatly the coefficient of vegetative reproduction.Low germinium concentration promoted growth of Dendrobium officinale protocorm, but high germinium concentration was on the contrary. Effects of germinium on the activities of antioxidase and the membrane system were obvious. Low germinium concentration enhanced the activities of protective enzyme, and maintained the stability of membrane systems. At higher germinium concentration, the activities of protective enzyme were suppressed, and the integrality of cell membranewas destroyed. Make use of protocorm of Dendrobium to establish rapidly multiplication bioreactor, the future of it's application will be expand.Isolated endophytic fungi from root of Dendrobium officinale and preliminary studied the effect of fungi, identitied some of fungi by rDNA ITS total sequence analysis. It is expected to provid an available approach for artificial cultivation of Dendrobium officinale.