转tcdA1B1杀虫基因的阴沟肠杆菌对4种农业害虫的杀虫活性与毒力

tcdA1B1为昆虫病原细菌一发光杆菌Photorhabdus luminescens的杀虫毒素基因。本文测定了转tcdA1B1基因的阴沟肠杆菌对甜菜夜蛾Spodoptera exigua、斜纹夜蛾Spodoptera litura、黄曲条跳甲Phyllotreta striolata和东亚飞蝗Locusta migratoria manilensis4种重要农业害虫的杀虫活性与毒力。在室内条件下，浓度为5．0×108cfu／mL的工程菌悬浮液，采用叶片浸渍法饲喂甜菜夜蛾2龄幼虫、斜纹夜蛾2龄幼虫、黄曲条跳甲成虫、东亚飞蝗2龄若虫，在11d、11d、15d、19d后的致死率分别为80．05％、81．83％、72．31％、39．74％；LT50分别为8．64d,8．38d、11．04d、28．22d。

Insecticidal activity and virulence of the transgenic Enterobacter cloacae with the insecticidal tcdA1B1 genes against four agricultural pests

The gene of tcdA1B1 is important insecticidal gene from entomopathogenic bacteria Photorhabdus luminescens. The pathogenicity of the transgenic Enterobacter cloacae with tcdA1B1 genes toward four agricultural insect pests (Spodoptera exigua, Spodoptera litura, Phyllotreta striolata, and Locusta migratoria maniLensis) was tested in this study. The transgenic E. cloacae showed variable virulence to the four insect pests. The mortalities of the 2~(nd) instar larvae of S. exigua and S. litura, the adults of P. striolata, and the larvae of L. migratoria man.ilensis were 80. 05%, 81. 83% , 72. 31%, and 39.74% after 11 d, 11 d,15 d, 19 d, respectively, and their LT_(50) values were 8. 64 d, 8. 38 d, 11. 04 d, and 28. 22 d, respectively, at the bacterial concentration of 5.0 × 10~8 cfu/mL, by leaf dip method. This transgenic E. cloacae showed high insecticidal activity to S. exigua, S. Litura and P. striolata and may be used for the potential biological control of these insect pests in the field.