Study On Isolation,Screening And Application Of Mycorrhizal Fungi In Anoectochilus Roxburghii

Anoectochilus roxburghii(Wall.)Lindl.was selected as material for the study on Mycorrhizal fungi symbiosis and pathogenic bacteria of stem rot for Anoectochilus roxburghii,tissue culture,Anoectochilus roxburghii-mycorrhizal fungi symbiotic system and its microscopic observation.The results were as follows:(1)Seven kinds of mycorrhizal fungi were isolated.They are Fusarium concentricum,Podospora sp,Schizophyllum commune,Cunninghamella elegans,Bjerkandera sp.PTY1,Rigidoporus vinctus and Cladosporium pseudocladosporioides through the morphological identification and DNA testing.All were found for the first time in Anoectochilus roxburghii(2)Determine the stem rot pathogenic bacteria of Anoectochilus roxburghii is Fusarium oxysporum.(3)The system of Anoectochilus roxburghii-mycorrhizal fungi symbiotic was set up by using 20g/L glucose to dilute the Fusarium concentricum in the hardend-seedling.The dilution ratio is three.(4)Microscopic observation showed that Fusarium concentricum through the root epidermis cell into the Anoectochilus roxburghii and they became hyphal knot in the roots of cortical cells.(5)Study on Anoectochilus roxburghii tissue culture demonstrated that the optimal proliferation medium was MS(only half of macro element)+Sucrose 2%+Banana 50g/L+Agar 0.9%+0.5mg/L 6-BA+0.5mg/L NAA+0.1mg/L GA3.These results not only provided a theoretical basis for the study of mycorrhizal fungi and Anoectochilus roxburghii symbiosis,would also provide a scientific reference for greenhouse and field planting of Anoectochilus roxburghii.