枯草芽孢杆菌G3菌株抑制立枯丝核菌菌核形成的影响因子分析

Factors Affecting Inhibition of Bacillus subtilis G3 Against SclerotialFormation of Rhizoctonia solani in Soil

产几丁质酶枯草芽孢杆菌G3菌剂在土壤中可抑制水稻纹枯病菌菌核形成。菌剂的适宜剂量为 1 1 5× 1 0 8cfu/g。温度、土壤含水量和菌剂处理的时间是影响效果的因素。 1 5～ 30℃培养 ,G3菌剂处理的菌核减退率从 35 2 %逐步上升到 77 8%。在 1 6 %～ 2 4 %土壤含水量的条件下 ,菌核减退率从 75 5%下降到 2 1 7%。接种病原真菌前施用G3菌剂比接种后效果更好。来源于湖南、山西、云南和上海的不同区域土壤对防效没有显著影响。菌剂添加豆粕粉、壳聚糖、葡萄糖和淀粉有不同程度的增效作用 ,尤其是壳聚糖 ,增效率达 2 9 2 %。

The factors affecting inhibition of the chitinase-producing Bacillus subtilis strain G3 against sclerotial formation of Rhizoctonia solani in soils was studied. Results indicated that appropriate rate of G3 preparation into soil was 0.25%, that was 1.15×10~8cfu/g. Reduction of sclerotia increased from 35.2% to 77.8% at the temperatures from 15℃ to 30℃, but decreased from 75.5% to 21.7% in the soil moistures from 16% to 24%. Treatment with G3 before R.solani inoculation into soil was more efficient than after R.solani inoculation. There was no differences in control efficacy when soil from Hunan, Shanxi, Yunnan and Shanghai were used, indicating that G3 might be applied in different area. G3 preparation amended with soybean powder, chitosan, glucose and corn starch showed increased control efficacy. Among the amendments, chitosan resulted in 29.2% increasement in control efficacy.