地衣芽孢杆菌W10抗菌蛋白对油菜菌核病菌的抑制作用及防病效果

Inhibition of antifungal protein produced by Bacillus licheniformis W10 to Sclerotinia sclerotiorum and control of rape stem rot by the protein

地衣芽孢杆菌（Bacillus licheniformis）W10培养菌液和滤液对油菜菌核病菌（Sclerotinia sclerotiorum）具有较强的颉顽能力。经硫酸铵沉淀和透析而提取的W10抗菌蛋白显著抑制病菌生长，当蛋白浓度为100μg·mL^-1时，对菌丝生长的抑制率在90％以上，菌核不能产生，处理菌核后菌核萌发推迟，明显抑制子囊孢子萌发和芽管伸长；当蛋白浓度为200μg·mL^-1时，对子囊的孢子萌发和芽管伸长的抑制率分别达46．0％和65．6％。经抗菌蛋白处理后，病菌菌丝出现形态异常甚至断裂；细胞膜透性改变，电解质渗漏而电导率增加。盆栽试验表明，抗菌蛋白对油菜菌核病有明显的防治效果，当蛋白浓度为3000μg·mL^-1时，防治效果达71．8％，与1000μg·mL^-1的多菌灵或腐霉利相当；抗菌蛋白与多菌灵或腐霉利3：1复配剂，当其浓度为1000μg·mL^-1时，防病效果为67．9％～70．1％。因此，地衣芽孢杆菌W10抗菌蛋白可作为防治油菜菌核病的一种新型生物农药单用或与多菌灵和腐霉利复配使用。

Isolate W10 of Bacillus licheniforrnis and its culture filtrate were strongly antagonistic to Sclerotinia sclerotiorurn causing rape stem rot. After the culture filtrate was precipitated with 30% ammonium sulfate and dialysed, the crude antifungal protein was obtained. The antifungal protein could significantly inhibit the mycelial growth of the pathogen. The mycelial growth decreased by over 90% when the protein concentration was 100μg·mL^-1, The sclerotial formation and germination could be inhibited by the antifungal protein. No sclerotia would be produced on the media supplemented with the protein of 100 μg·mL^-1, The antifungal protein could obviously hinder the ascospore germination and the tube stretch, with the inhibition rate of 46.0% and 65.6%, respectively. Also, the hyphae of the pathogen was deformed and cracked after being treated by the antifungal protein, leading to cytoplasm leakage and electrical conductivity increase. The test showed that the antifungal protein could well control rape stem rot, with the control effect of 71.8% at the concentration of 3 000μg·mL^-1, as carbendazim and procymidone did at the concentration of 1 000 μg·mL^-1. The mixure （3 ： 1） of the antifungal protein with earbendazim or procymidone at the concentration of 1 000 μg·mL^-1 had the control effect of 67.9 %- 70. 1% on the disease. Thererfore, the antifungal protein produced by B. licheniformis W10 could be used as a new bio-fungicide to control rape stem rot.