Study On Selection And Utilization Of Antagonistic Bacteria To Colletotrichum Lindemuthianum

117 bacterial strains have been isolated from the root soil from Nongda, Nanyue, Xiangyinand Liuyang. The inhibiting effects of these actinomyces against colletotrichum lindemuthianumhave been tested. The result shows that 23 strains are effective, which have been preliminaryproved to be Streptomyces.After preliminary selection and the tests of fermentation fluid to colletotrichumlindemuthianum, SF12, SF19 and XF11 have been selected to inhibit colletotrichumlindemuthianum obviously.Antagonistic effect tests indicated that Actinomyces exist widely inthe root soil, but those own strong antagonistic effect are extremely scare.The best culturecondition and method of SF12, SF19 and the XF11 have been given. And the best fermentationcondition has been determined.The culture time of SF12 and the SF19 are both 72h, and the bestculture medium is 2nd culture medium. The suitable conditions for Actinomyces growing were27±1℃with 7.0 pH and vibration for the whole day. The culture time of XF11 is 72h, and thebest culture medium is 1st culture medium. The suitable conditions for Actinomyces growingwere 27±1℃with 7.0 pH and vibration for the whole day. The function mechanism researchindicates SF12, SF19 and the XF11 fermentation fluid can antagonist mycelium growth andspore sprouting of colletotrichum lindemuthianum. Indoor experiments show the fermentationfluid has the function to promote seed sprouting.Through in vitro shoots and potted plants tests, XF11 fermentation fluid can reducecolletotrichum lindemuthianum anthrax condition. In vitro shoots test indicated that antagonisticrates were 72.3％and 73.3％separately, while inoculate colletotrichum lindemuthianum after 1day and 3 days. It means XF11 has quite stable inhibitory action. The pot experiment resultindicated XF11 fermentation fluid has the better protective function to colletotrichumlindemuthianum. At 6000mg·L^-1, the protective function rate are all above 60％. Along withreduce of the density, the effect also rapidly dropped. But treat function dropped quicker thanprotect function, and there was no effect under low density.