Screening and Identification of the Endophytic Bacteria Bacillus velezensis Against Tea Anthracnose

Seven strains of endophytic bacteria were isolated and purified from the healthy leaves of 'Xinyang 10' Camellia sinensis in parent field of Xiangyun tea base. Four target strains of endophytic bacteria with inhibitory effect on Colletotrichum fructicola were screened by the flat-stand method. The endophytic antagonistic bacterium named X10-03 significantly inhibited the vegetative growth of C. fructicola with an inhibition of 52.7%. Optical microscope showed that both mycelial growth and conidia germination of C. fructicola were inhibited by the metabolites of strain X10-03. The strain X10-03 fermentation broth in 3-fold diluted concentrations suppressed the mycelial growth of C. fructicola with a suppressive rate of 70.4%. The X10-03 strain was identified as Bacillus velezensis by morphological observation, 16S rDNA and gyrA gene sequences analysis.