Abstract:

Citrus green mildew is the main diseases of citrus in storage period. In order to use antagonist endogenous bacteria for biological control, in this study, 26 endophytic strains were isolated from the Citrus skins of three selected varieties using the method of grinding liquid culture. By confrontation culture method, seven endophytic strains had obviously antagonism against Penicillium italicum, accounting for 19.2% of the total. Preliminary identification showed the 5 strains belong to Aerobacillus sp.，Bacillus sp., Aeromonas spp., Pseudomonas spp. and Xanthomonas spp., respectively. The occurrence frequency of antagonistic endophytes in different varieties of Citrus was different. Bacteriostatic results showed that bacteriostatic circle diameter of H-3 was the largest, reached 15.3 mm, and that of H-18 was the smallest, only 5.6 mm after cultivated for 3 days; after 4 days, each bacteriostatic circle diameter were narrow, but narrow range was not too much; after 5 days, antagonistic effects of H-3 was still evident, its bacteriostatic circle diameter was 10.3 mm. By morphologic and physiological characteristics, especially by the analysis of 16S rDNA sequences, H-3 was identified as Bacillus subtilis. The found of the endophytic bacterium of H-3 had good application value on biological control of blue mold of Citrus.