枯草芽孢杆菌G3str菌株在有机硫熏蒸土壤中的繁殖及其对病原真菌的抑制作用

生防菌枯草芽孢杆菌G3^str。菌株与营养添加剂混配使用，在经有机硫土壤熏蒸剂“大扫灭”熏蒸过的土中有一定的增殖，增殖量大于不熏蒸的自然土。同时，在加入菌剂的前6d，灭菌土中脂肽和伊枯草菌素检测量高于自然土。抑制水稻纹枯病菌菌核形成试验表明，G3^str菌增殖过的灭菌土比不增殖的对照有更强的抑菌作用。盆栽试验结果表明，土壤中添加G3^str。菌显著减轻由腐霉引起的茄子猝倒病，土壤熏蒸加强防病效果。

The Multiplication of Bacillus subtilis G3str in the Soil Fumigated with Organic-sulfur Fumigant and Its Inhibition against Phytopathogenic Fungi

The organic-sulfur fumigant Dazomet could effectively reduce the population of bacteria, fungi and nematodes in soil. Bacillus subtilis G3^str as a biocontrol strain could multiply in soil fumigated by Dazomet with addition of nutritional amendment. The enhanced population of G3^str in sterile soil was higher than that in non-sterile soil. In the first six days after addition, the amount of lipopeptides and iturin were at a higher level in sterile soil than in non-sterile soil as well. Sclerotia formation by Rhizoctonia solanl in soils was greatly inhibited in fumigated soil amended with G3^str compared with fumigated soil without G3^str. Pot trials indicated that Pythium aphanidermatum damping-off of eggplant was significantly reduced by addition of G3^str and was enhanced by fumigation. Combination of fumigation with biocontrol agents was suggested as an effective way for control of soil-bome plant diseases.