植物内生枯草芽孢杆菌Em7菌株对葡萄灰霉病菌的抑菌活性

通过室内皿内对峙抑菌试验、分生孢子萌发抑制试验、离体果实接种试验以及电镜技术，研究测定了分离自小麦根部的植物内生枯草芽孢杆菌Em7菌液对葡萄灰霉病菌Botrytiscinerea Pers.的抑制作用及抑菌机理。结果表明:用Em7菌液处理葡萄灰霉病菌后，在PDA培养基上形成了明显的抑菌圈，直径达2.81 cm；菌液对分生孢子萌发的抑制率达到88.65%；经Em7菌液处理后，离体果实病情指数明显低于空白对照，相对防治效果达到78.92%。电镜观察发现，处理组菌丝生长异常，体表凹凸不平，局部膨大成结或缢缩，分枝变多，菌丝体内液泡增多，细胞壁增厚，细胞膜透性发生变化。表明植物内生枯草芽孢杆菌Em7菌株对葡萄灰霉病菌有良好的抑制作用，并且可以有效控制葡萄灰霉病的发生。

Antifungal activity of plant endophytic Bacillus subtilis strain Em7 against Botrytis cinerea

The inhibition effect of plant endophyte Bacillus subtilis strain Em7, isolated from wheat roots, against Botrytis cinerea Pers. was studied, by using the antifungal test on medium plates, inhibition test of conidia germination, in vitro inoculation on fruit, and observation with electron microscopy. Confronting incubation of B. subtilis Em7 and B. cinerea on PDA medium resulted in obvious inhibition zones, with the diameter of 2.81 cm. Em7 treatment led to 88.65% failure germination of the B. cinerea conidia. In vitro inoculation assay verified that Em7 treated B. cinerea exhibiting reduced pathogenicity on grape fruit with a lower disease index, and the relative control effect reached 78.92% compared to the controls. Moreover, scanning electron microscopy observation revealed a malformed morphology of the Em7 treated fungus mycelium, with an uneven surface, a local swelling node or constriction, more branches, increased vacuoles, thicken cell wall, and altered cell membrane permeability. The plant endophytic B. subtilis Em7 can effectively inhibit B. cinerea and reduce the fungus pathogenicity.