叶面喷施枯草芽胞杆菌XF-1防治大白菜根肿病

Control of cabbage clubroot by foliar-spaying with Bacillus subtilis XF-1

为了建立简易、有效的根肿病生防体系,本研究采用浇灌和喷施枯草芽胞杆菌XF-1的绿色荧光蛋白标记菌株XF-1-gfp,测定其在大白菜植株内的定殖能力,并用野生型菌株XF-1发酵液研究其防治根肿病和挽回产量效果。结果表明,叶面喷施XF-1-gfp发酵液后,标记菌在大白菜根、茎、叶等组织内的密度呈现出"先上升后下降最后趋于平稳"的趋势,最终稳定在约10~3 cfu/g组织;盆栽试验结果表明,与空白对照相比,所有处理发病率和病情指数均显著下降,喷施XF-1发酵液后最佳防治效果为56.4%,浇灌化学杀菌剂10%氰霜唑悬浮剂2 000倍液及1×10~7 cfu/mL的XF-1发酵液防效分别为78.6%与70.7%。大田试验结果表明,喷施XF-1发酵液后防治效果达52.6%,与浇灌化学杀菌剂10%氰霜唑悬浮剂(64.6%)及XF-1发酵液(74.0%)相比无显著差异。此外,与空白对照、浇灌10%氰霜唑悬浮剂及XF-1发酵液相比,喷施XF-1发酵液后大白菜单株产量分别增加了74.0%、35.1%及23.6%。试验结果表明叶面喷施XF-1发酵液是一种有效的防控大白菜根肿病及增产增收的方法。

To establish an effective and simple biocontrol management system in the field, the colonization ability of XF-1 was tested in Chinese cabbage by drenching and spraying XF-1- gfp and clubroot control and yield recovery effects were studied by drenching and spraying the wild strain XF-1 in the pot and field experiments. The results showed that its population in root, stem and leaf of cabbage after foliar-spraying had a rising trend first, then decreasing and leveling off, and finally the colonization density kept at 10 3 cfu/g tissues. The incidence rate and disease index had a significant decline compared to the negative control in the pot experiment with 56.4% of control effect by spraying XF-1, 78.6% and 70.7% by drenching 2 000 times dilution of cyazofamid and 1×10 7cfu/mL of XF-1. The disease control effects were 52.6%, 64.6% and 74.0%, respectively, in the field experiment without significant difference. Moreover, spraying XF-1 increased yield by 70.4%, 35.1% and 23.6% compared with the negative control, drenching cyazofamid and XF-1, respectively. This study suggested that foliar-spray of XF-1 might be an effective way for controlling clubroot and increasing Chinese cabbage yield.