苏云金芽胞杆菌工程菌WG-001可湿性粉剂的增效化合物筛选

为了筛选出对苏云金芽胞杆菌具有增效作用的无机化合物,并确定其最佳使用浓度,于苏云金芽胞杆菌工程菌WG-001可湿性粉剂(Bt WG-001 WP)中添加MgCl2、CaCl2、NaHCO3、MgSO4、NaH2PO4、Na2CO3、Na2HPO4、KH2PO4等8种化合物,测定其对小菜蛾的毒力.结果显示,添加0.4％MgCl2、0.2％CaCl2、0.4％MgSO4、0.2％Na2CO3时,共毒因子分别为46.75、36.27、41.51、31.03,均大于20,而添加另外4种化合物,共毒因子均低于20；添加0.4％MgCl2、0.2％CaCl2、0.4％MgSO4、0.2％Na2CO3,增效比最大,分别为1.46、1.33、1.34、1.29.田间试验结果显示,Bt WG-001 WP中添加0.4％MgSO4稀释500倍施用时,药后7天对小菜蛾的田间平均防效最高,为80.51％,且与其它处理差异显著.表明添加0.4％MgSO4可显著提高Bt对小菜蛾的田间防效.

Screening of synergistic inorganic compounds for Bacillus thuringiensis engineering strain WG-001 WP

To screen synergistic and optimal application concentration of inorganic compounds for Bacillus thuringiensis engineering strain WG-001 against diamondback moth, Plutella xylostella, toxicity of Bt WG-001 WP to P.xylostella containing inorganic compounds, such as MgCl₂, CaCl₂, NaHCO₃, MgSO₄, NaH₂PO₄, Na₂CO₃, Na₂HPO₄, KH₂PO₄, was evaluated. Results showed that co-toxicity factors of 0.4%MgCl₂, 0.2% CaCl₂, 0.4%MgSO₄ and 0.2%Na₂CO₃ with Bt WG-001 WP were 46.75, 36.27, 41.51 and 31.03, respectively. While the other 4 kinds of inorganic compounds had no synergetic action to Bt WG-001 WP against P.xylostella. Synergistic ratios of 0.4%MgCl₂, 0.2%CaCl₂, 0.4%MgSO₄ and 0.2%Na₂CO₃ with Bt WG-001 WP were 1.46, 1.33, 1.34 and 1.29 respectively. Results of field test showed that average control effect of 500 dilution of Bt WG-001 WP containing 0.4%MgSO₄ against P.xylotella was 80.51% on the 7th day after spraying, and it had significantly difference from other treatments. The result indicated that 0.4% MgSO₄ could significantly increase field control efficacy of Bt WG-001 WP against P.xylotella.