Two Orchid Tissue Culture And Screen Beneficial Mycorrhizal Fungi

As an important plant resources, the orchidaceae has high rnamental value and medicinal value and alarge market demand. The orchidaceae has low rate of the seed germination in natural state, tissue CultureTechnique makes orchid increased number, but tissue culture seedling has slow growth and low survivalrate because of ack of symbiontmycorrhizal fungi. This study aims to using mycorrhizal techniques and thecombined technique of tissue, prompting orchid cultivation seedlings mycorrhizal, different plants were thebeneficial blanc mycorrhiza. The major achievements are as follows:1The germination rate of Cymbidium goeringii seeds treated with NaOH and150-day darkness washigh as79.2%in asymbiotic culture.The1/2MS medium with2.0mg·L^-1NAA+1.0mg·L^-16-BA was the bestmedium for rhizomes induction of Cymbidium goeringiii; The1/2MS medium with0.1mg·L^-1NAA+1.0mg·L^-16-BA was the best medium for differentiation of Cymbidium goeringiii; The1/2MSmedium with0.1mg·L^-1NAA+1.0mg·L^-16-BA was the best medium for rooting and strong sprouts ofCymbidium goeringiii‘. The1/2MS medium with coconut milk was the best for rooting and strong sproutsof Dendrobium officinale.2Tissue culture seedlings of the Dendrobium officinale were inoculated with eight fungal strains. Thefresh weight, drgmatter weight, nutrition elements and the number of root and buds inoculated with FL3、FL7、FL8strains inereased significantly. And the three strains were obtained by paraffin section mieroscopeand recovery, It seemed that the strains FL3、FL7、FL8associated with the Dendrobium officinale well.3Tissue culture seedlings of the Cymbidium goeringii were inoculated with three fungal strains. Thefresh weight and the number of root and buds inoculated with FL2strains inereased significantly. And theFL2strains were obtained by paraffin section mieroscopeIt seemed that the strains FL2associated with the Cymbidium goeringii well..4The observation of the mycorrhizal microstructure of Dendrobium officinale showed that it belongedto the typical mycorrhiza of orchids. The fungus observed within the root after15d fungus inoculated withtissue culture seedlings.The infection pathway started with the invasion of the fungi into the velamen andthen entered the velamen tissue by root hair or breaking the velamen. The hyphae penetrated through thewall of cortical cells and continuously spread inwards.5The observation of the mycorrhizal microstructure of Cymbidium goeringii showed that it belongedto the typical mycorrhiza of orchids. The infection pathway started with the invasion of the fungi into thevelamen and then entered the cortical tissue by breaking the velamen. The hyphae penetrated through thewall of cortical cells and continuously spread inwards.