贝莱斯芽孢杆菌YJK1鉴定及其对茶炭疽病的拮抗效果

Antagonistic Activity and Utilization of Bacillus velezensis Strain YJK1 as A Biocontrol Agent Against Anthracnose on Camellia sinensis

茶树炭疽病的发生严重威胁着茶产业的可持续发展,传统的化学农药防治方法存在农药残留和环境污染等问题。以筛选到的贝莱斯芽孢杆菌(Bacillus velezensis)YJK1生防新菌株为研究对象,探究了YJK1菌株对茶树病害的生物防治效果。平板拮抗试验发现YJK1菌株对茶树炭疽菌(Colletotrichum camelliae)、果生炭疽菌(Colletotrichum fructicola)、藤黑镰刀菌(Fusarium fujikuroi)等多种茶树真菌病害具有明显的抑制效果。YJK1发酵稀释液对茶树炭疽菌和果生炭疽菌孢子具有明显的抑制作用。喷施贝莱斯芽孢杆菌YJK1发酵液对白叶1号和黄金芽离体叶片的炭疽病病菌生长抑制效果明显,先喷施YJK1菌株发酵液再接种茶树炭疽菌,病菌生长抑制率为78.1%,同时喷施发酵液和接种炭疽菌,抑制率为61.8%。结果表明,YJK1菌株对茶树炭疽病“防”和“治”效果均显著。YJK1发酵液对多种真菌具有广谱性,稳定性测试结果说明发酵液中活性物质在80℃以下保持稳定;紫外处理60 min后抑制率仍高于50%;经不同pH处理后,当pH为5~11时,抑制率无显著区别。综上,贝莱斯芽孢杆菌YJK1在茶树绿色农业生产领域具有较好的应用潜力。

The tea industry is one of China's important agricultural economic resources.However,widespread outbreaks of anthracnose on Camellia sinensis pose a significant threat to the sustainability of the tea industry.Conventional approaches based on chemical pesticides face inherent challenges,including pesticide residue accumulation and environmental pollution.In this study,the biological control effect of Bacillus velezensis YJK1 on tea tree diseases was evaluated.The results demonstrat that the YJK1 isolate exhibited robust antagonistic activity against fungal diseases affecting tea trees,particularly against pathogens such as Colletotrichum camelliae,Colletotrichum fructicola and Fusarium fujikuroi.YJK1 fermentation diluent has a significant inhibitory effect on the spores of C.camelliae and C.fructicola.The inhibitory effects of YJK1 fermented liquid on the diameter of C.camelliae were evaluated with the detached tea leaves.YJK1 fermented liquid effectively prevented tea tree anthracnose with 78.1%control when applied 24 h before C.camelliae inoculation and 61.8%during simultaneous inoculation.However,its efficacy was limited(post-inoculation).The YJK1 fermentation broth has a broad-spectrum of activity against various fungi.The antagonistic activity of the fermented liquid was stable below 80℃.After 60 min of UV treatment,the inhibition rate was still above 50%.And after treatment with different pH values,there was no significant difference in the inhibition rate within the pH range of 5-11.These findings suggest that B.velezensis YJK1 is a promising biocontrol agent for the management of tea plant diseases.