Diversity Research Of Endophytes And Broad-spectrum Antagonistic Bacterias Screening From Banana

The temperature of Banana orchards is generally damp that broke various diseases out easily, serious infect the production and quality of banana. Fusarium oxysporum f. sp. Cubense is the most damaging disease. Biological of efficiency and safety, biological control is the one of the important methods for the prevention and control of banana fusarium wilt. The combination of relationship had been set up in plant and endophytes that residnent in plant. On the one hand, plant growth to provide the necessary nutrients and energy to endophytes that lived in. On the other hand, metabolites can be released by endophytic that worked on plants. So the research of banana endophytic diversity and using of bio-control bacteria which is safe and effective has important practical significance.In order to determine the diversity of endophytes which we obtained from healthy and diseased tissues of two disease-resistant and one disease susceptible banana cultivars,that were separated from roots, corms, pseudostems, leaves. T-RFLP was used to analyze diversity of microbial community and qualitatively analyze the primary microorganisms in the banana samples. Antagonistic actinomycetes were isolated by pour plate method from soil samples, and selected by confrontation culture method against Fusarium oxysporum f. sp. Cubense Race4. Activity assessment of antagonistic streptomyces against Fusarium oxysporum f. sp. Cubense, Curvularia lunata, Curvularia fallax, Corynespora cassiicola (Berk&Curt) Wei, Alternaria musae, Deightoniella troulosa, Colletotrichum musae, Pestalogiopsis sp., Btoryosphaeria dothidea was determined by the methods of flat growth restraint, mycelial growth and spore germination. Taxonomy identification of041,04-1,19-1,03A-lwas conducted by evaluating morphologic characteristics, cultural traits, physio-biochemical characteristics and16sRNA gene sequences for phylogenetic analysis. The main conclusions are as follows:(1) T-RFLP was used to banana simples that choosing Hha I enzyme was batter than Msp I enzyme because more effective TRFs fragments we can obtain.(2) As a result of pathogen infection, endophytic in each banana cultivars had obvious changes and the amount and type of endophytic bacteria in poor stability.(3) There had the7same dominant populations in different banana cultivars and most dominant population distribution in different varieties of each are not identical, population diversity had certain advantage.(4) The total of isolates showed that we obtained approximately240strains bacteria, followed by142strains actinomycetes, and56strains fungi. Bacteria are dominant population of banana endophytes and the fungi in all the varieties of the most widely distributed(5) Ten actinomyces and two bacteria were determined to possess antibiotic activity against10banana pathogens. The radius of inhibition zone of strain041on PDA plates ranged from28.13±1.89mm. The inhibition rates to mycelium growth of pathogenic fungus ranged from9.85%. Isoltaes041and04-1were identificed as Streptomyces misionensis, the strain19-1as Streptomyces antibioticus, and the strain03A-1as Streptomyces griseoruber.