Abstract: Mango stem-end rot disease is mainly caused by Botryodiplodia theobromae in Hainan. Two antagonistic bacteria strains (HBW and HBR) were isolated from the mango fruits in Hainan Province. They were identified according to morphological observation, physiological and biochemical characteristics, and consequences of 16S rRNA homologous analysis. The antagonistic activities of the bacterial suspensions in the two bacteria strains were characterized using in vitro antagonistic tests. The inhibiting effect on B. theobromae differing in carbendazim resistance were tested by the bacterial suspension and cell-free culture filtrate. The results showed that two strains of HBW and HBR were identified as Bacillus amyloliquefaciens. They exhibited higher antifungal activity, which strongly inhibited the growth of many plant pathogenic fungi. The bacterial suspension and diluted culture filtrate were effective to carbendazim-resistant and -sensitive strains of B. theobromae. The diluted culture filtrates had higher inhibiting effect compared with the bacterial suspension, and the highest inhibition rate of 20% culture filtrate of the HBW strain reached 100%. The two strains of B. amyloliquefaciens (HBW and HBR) had good potential for development and application.

Key words: Bacillus amyloliquefaciens, antagonistic activity, carbendazim resistance, Botryodiplodia theobromae

摘要： 海南地区芒果蒂腐病主要由可可球二孢菌（Botryodiplodia theobromae）引起，从海南芒果上分离获得2株拮抗细菌（HBW和HBR），采用形态学、生理生化特性和分子检测等方法对菌种进行鉴定，通过离体活性测定法评估其对10种植物病原真菌的拮抗活性，并进一步比较了细菌悬液和无菌培养滤液对具有不同多菌灵抗性的可可球二孢菌株的抑菌效果。结果表明， 拮抗细菌HBW和HBR均属于解淀粉芽孢杆菌（Bacillus amyloliquefaciens），对10种植物病原真菌均具有较强的抑制作用。HBW和HBR的细菌悬液和无菌培养滤液对具有不同多菌灵抗性的可可球二孢菌均有较好的抑制效果，且培养滤液的抑菌效果优于悬浮液。其中，20%的稀释滤液最高抑制率可达100%。由此表明，解淀粉芽孢杆菌HBW和HBR菌株具有较高的开发应用潜力。

关键词: 解淀粉芽孢杆菌, 拮抗活性, 多菌灵抗性, 可可球二孢菌