香蕉枯萎病生防菌绿头枝孢菌LS1的筛选鉴定

【背景】香蕉枯萎病是一种真菌土传毁灭性病害,由于抗病品种产量普遍不佳和化学防治易污染环境等系列问题,生物防治是其理想的防治方法。【目的】筛选抗香蕉枯萎病的深色有隔内生真菌(Dark septate endophytes,DSE)菌株,丰富生防菌株资源库。【方法】采用平皿和盆栽实验方法评价5株DSE对香蕉的促生作用和对香蕉枯萎病的防治效果,采用形态学和分子生物学相结合的方法对优良菌株进行分类鉴定。【结果】接种DSE可有效促进香蕉植株的生长,尤以菌株LS1作用最显著,接种后鲜重与干重分别比对照增加47.36%与42.40%;接种DSE可有效提高植株对香蕉枯萎病的抗性,其中菌株LS1处理的香蕉植株表现的防治效果显著优于其它菌株,平皿中的防效为86.19%,盆栽实验防效为63.19%;结合形态学和分子鉴定技术,将菌株LS1鉴定为绿头枝孢菌Cladosporium chlorocephalum。【结论】LS1是一株具有开发利用价值的香蕉枯萎病生防菌株。

Screen and identification of biocontrol strain Cladosporium chlorocephalum LS1 against banana Fusarium wilt

Background] Banana Fusarium wilt is a devastating disease caused by the soil-borne hyphomycete, Fusarium oxysporum f. sp. cubense (Foc). Due to the low production limitation of resistant cultivars and attempts to control Fusarium wilt with chemical fungicides have proved uneconomic and are environmentally unfriendly, using novel strategies such as biological control is attractive alternatives to conventional control methods. Objective] In order to select dark septate endophytes strains that showed significantly antagonistic effect on the Foc growth and to enrich the microbial resources for biocontrol. Methods] Five dark septate endophytes strains were selected for evaluation of banana growth promotion ability and control efficacy against the Fusarium wilt through culture dish and pot culture method, and the dominant strain LS1 was identified based on morphological characteristics and ITS sequence analysis. Results] All the five dark septate endophytes strains have the ability to carry out banana growth promoting activities after the inoculation, but the strain LS1 function most notably, which indicated by the seedling fresh weight and dry weight were increased by 47.36% and 42.40%, separately. The disease control efficacies of LS1 against the Fusarium wilt was found up to 86.19% in the culture dish and 63.19% in the pot culture method, which were significantly higher than other dark septate endophytes strains. Morphological observation and ITS sequence alignment analysis results showed that the LS1 strain belonged to Cladosporium chlorocephalum. Conclusion] These results indicated that the strain LS1 promised to provide a new biological control method for banana Fusarium wilt disease.