Screening, identification and control efficacy of antagonistic bacteria against Colletotrichum gloeosporioides on mango.
Pan ZhaoBo, Li QiLi, Mo JianYou, Guo TangXun, Huang SuiPing, Wei JiGuang
Author Affiliation: Institute of Plant Protection, Guangxi Academy of Agricultural Sciences, Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests, Nanning 530007, Guangxi Zhuang Autonomous Region, China.
Acta Phytophylacica Sinica 40 : 517-522
Abstract : In order to seek more effective antagonistic bacteria, 104 bacterial strains were isolated from the spots of powdery mildew on the leaves of cucurbit, 16 strains of antagonistic bacteria were screened out by confrontation PDA plates and their antifungal activities were tested in eight different culture media. The strains 9A, 26A and 4N with better antifungal activity were selected for disease control test, and 9A, 26A strains with better control efficacy were identified. The results showed that 9A, 26A and 4N strains cultured respectively in pumpkin, sweet potato and potato media had the best antifungal activity, with the inhibition rates of 88.83%, 87.83% and 85.87%, respectively, against mycelial growth of C. gloeosporioides. Detached mango fruits were treated with the suspension of 9A, 26A and 4N at 24 h before inoculation of the suspension C. gloeosporioides, and the control efficacy were both 100%, with the same result from the treatment with prochloraz (EW). The control efficacies of 9A and 26A were 98.4% and 90.5%, respectively, on fruits in field, which were significantly higher than those of the treatment with prochloraz (EW), but the control efficacy of 4N treatment was 58.2%. The strains of 9A and 26A were identified as Bacillus subtilis based on morphological, physiological and biochemical characteristics and phylogenetic analysis of 16S rDNA sequences. The results indicated that 9A and 26A strains have better bio-control value.