Study On Several Cymbidium Plants Tissue Culture And Cymbidium Goeringii Mycorrhizal Fungi

Chinese orchids generally refer to part of the terrestrial orchids of Cymbidium, such asC. goeringii, C. faberi, C. ensifolium, C. sinense, C. kanran, with high ornamental valueand economic value. China is rich in native species and cultivars resources. Mycorrhizalfungi establish mutually beneficial symbiosis relationship with orchids under naturalconditions, and play a crucial role in completing orchids life cycle. The purpose of thisstudy is to analyze the factors influencing on orchid tissue culture, and establish symbioticsystem with orchids and mycorrhizal fungi by artificial inoculation to explore its symbioticeffects. The main achievements are as follows:1. The best medium for rhizome multiplication and bud differentiation of C. kanranwas MS with6-BA1.5mg·L-1and NAA0.3mg·L-1; the best medium for rhizomemultiplication and bud differentiation of C. faberi was MS with6-BA1.0mg·L-1andNAA0.3mg·L-1; during the C. goeringii tissue culture process, it’s found that1/2MS as thebasic medium with6-BA0.1mg·L-1, NAA5.0mg·L-1and AC1.0g L-1is best for therhizome multiplication; with6-BA1.0mg·L-1and NAA0.3mg·L-1is best for the rhizomebud differentiation; with IBA1.0mg·L-1and AC1.0g L-1is most conducive to its seedlingrooting.2. Tissue cultures of C. goeringii were induced on culture medium with the fungalelicitor. Mycorrhizal fungal elicitors isolated from the root of wild C. goeringii play asignificant role on promoting rhizome multiplication and bud differentiation.3. Plantlets in vitro of C. goeringii were co-cultured with12fungal strains by artificialinoculation. After inoculated with strains FC11for two months, the biomass of theseedlings increased significantly, as well as carbohydrate, water and nutrient elementscontents., while promoting the differentiation of seedling root. By observing paraffinsections and re-separation results, it seems that the strain can formed a symbiotic systemwith C. goeringii plantlets.4. Different varieties of C. goeringii tissue-culture seedlings were inoculated withmycorrhizal fungi. After inoculated for two months, the results show that under the same fungal strains,‘yeyi’ can grew better with mycorrhizal fungi, but ‘huanqiuheding’ grewweaker with mycorrhizal fungi.5. By observation the mycorrhizal structure of C. goeringii, it’s found that it had thetypical mycorrhiza of orchids. The infection pathway began with the invasion of thehyphae into the velamen and then entered the cortical tissue by breaking the velamen orthrough the root hair; peloton colonized in the epithelial cells and often occurred near thenucleus or twisted with them together; The hyphae penetrated through the cell wall toinfect other cells, and twined agglomerated again.