神农架原始森林高毒力苏云金芽孢杆菌菌株分离鉴定研究

Study on Isolation, Identification and Toxicity to Inset Larve of Bacillus Thuringiensis in the Shen Nong Jia Primitive Forest Aera, Hubei Province

目的 :调查湖北神农架原始森林苏云金芽孢杆菌 (简称B .t)天然资源 ,以期发现新的B .t亚种或毒力特异性菌株。方法 :B .t的分离采用热处理筛选法 ,高毒力菌株的筛选采用常规生物测定程序。B .t亚种鉴定采用血清学反应和常规生理生化反应方法。结果 :从神农架原始森林 160份不同生态类型的土壤样品中 ,共分离出B .t 18株 ,从中筛选出 8株高毒力菌株 ,较国内对棉铃幼虫高毒力生产菌株HD - 1而言 ,菌株A3 、B4、C5 、C6 、D2 和E6 对夜娥科 3种害虫 (棉铃幼虫、斜纹夜蛾、甜菜夜蛾 )均具有相对较高毒力 ,其中A3 、B4对棉铃幼虫具显著高毒力水平 ,毒力指数分别为 2 .98和 4.2 6,C5 和C6 对斜纹夜娥和甜菜夜蛾有较高毒力 ,菌株F3 和F8对致倦库蚊较国内生产高毒株HD - 5 67有相对较高的毒力水平 ,毒力指数分别为 13.7和 16.4,经生理生化反应和血清学反应鉴定 ,A3 属于H3abc型 ,F3 和F8属H1 4 型 ,A3 、B4、C5 、C6 、D2 、E6 属H7型。结论 :神农架原始森林高毒力B .t菌株分离 ,进一步丰富了我国B .t的天然资源 。

Objective:To investigate Bacillus Thuringiensises in the Shen Nong Jia primitive forest area, Hubei province. Method:Normal bioassay. Result:The two isolates (A 3 and B 4) which belong to Bt H 3abc and Bt H 7 were more toxic to larvae of heliothis armigera than that of Bt HD-1. The toxicity of them is respectively 2.98 and 4.26 times that of Bt HD-1; The two isolates (C 5 and C 6) which belong to Bt H 7 were more toxic to larvae of spodoptera litura and spodotera exigua; The two isolates (F 3 and F 8) which belong to Bt H 14 were more toxic to larvae of Culex fatigans. And the toxicity of them is respectively 13.7 and 16.4 times that of Bt HD-567.Conclusion:It was reported that B.t was isolated and identified from the region. This provides the good basis of future studying and applying the new microbiopesticides.