The Identification Of Mycorrhizal Fungi From Dendrobium Sinense And The Influence Of Which For Orchid And Oncidium Seedling

Orchidaceae is a typical endogenous mycorrhizal plants, at the same time, many species of which have ornamental and medicinal value. While in the natural environment, orchid seed germination and seedling growth must have the help of mycorrhizal fugin.Because of its value of excessive excavation by human and ecological environment destruction, almost all wild orchids are confronted with exhausted, including Dendrobium sinense. With fungus companion and mycorrhizal nutritional properties, to study the species identification of fungi and fumble with the orchid symbiotic relationship can be the highly significant for protection of endangered species of wild orchid work. However, most of the mycorrhizal fungi are endogenous without spores, there are great limitations in using morphology methods for further identification of mycorrhizal fungi.Therefore unknown fungi being determined by molecular biology techniques, can make up for the deficiency of the morphological identification, which could provide theoretical support to screen symbiotic fungi.To explore the symbiotic fungi with Dendrobium sinense, and then grope for fungi being more useful in the Dendrobium sinense cultivation, application of rapid propagation and conservation work,this study seperated13fungi from Dendrobium sinense’s bulbs, using morphological and molecular identification to screen2useful fungi;Using HPLC method to detect free amino acid in the fermented liquid of the2strains, and mixed strains fermentation liquid to Oncidium bulbs to test the screening fungi be more beneficial for the growth of orchid.The main research results are as follows:(1) The molecular identification.According to the morphology and molecular biology identification methods, S1was identified as Tulasnellaceae fungus, Z3was identified as Epacris pulchella root associated fungus;(2) HPLC to detect free amino acids content in the fermented liquid of S1and Z3.17kinds of amino acids were detected in PDB and DE fermented liquid of S1and Z3, amino acid content has the highest amount in the PDB fermented liquid of S1,while has the highest amount in the DE fermented liquid of Z3.(3) Mycorrhizal infection. Inoculated S1and Z3back to Dendrobium sinense seedlings, after the90d the statistics found is that seedling survival rate on73.3%by S1, while seedling survival rate on36.7%by Z3.Using staining fuchsin method to analyse the mycorrhizal dyeing and microscopic observation, the results showed that the seedlings roors had signs of infection by the two strains.(4) Detecting the thickness、width and height of Oncidium bulbs, the chlorophyll content and root activity.Irrigating S1, Z3and W5fermented liquid on Oncidium seedlings, and detecting thickness, width and height of Oncidium bulbs,the results showed that S1in MS has obviously promoting effect;Chlorophyll content were without apparent promoting effect by three strains;Z3in MS has obvious promoting role for root activity.Three strains in MS and DE fermented liquid had more influence on root activity than CK.