转基因棉Bt毒性表达的时空动态及对棉铃虫生存、繁殖的影响

Toxic Reponse of Cotton Bollworm to Various Parts of Bt-transgenic Cotton in Different Growing Stages

转Ｂｔ基因棉３１０品系在不同发育阶段，对棉铃虫的毒性表达测定表明，（１）棉株各空间组织在不同发育阶段均能强力阻止棉铃虫取食，表达出较高的抗虫效果。（２）棉株不同空间组织在同一时期，毒性表达存在差异，以营养组织，中、小蕾高于大蕾和铃。（３）同一组织毒性表达随着棉株生长、发育、成熟、衰老逐渐呈动态下降。（４）前后各阶段，同一组织饲喂棉铃虫，死亡所需要天数呈动态增加，但最终生存率降低到一个较低水平。存活老熟幼虫重量、蛹重及蛹羽化率比对照棉铃虫下降３０％～５０％，羽化的蛾子进行自交或异交均能产下受精率、孵化率很高的卵。取食Ｂｔ转基因棉的雌蛾产卵量比对照减少５０％～７０％。

Various parts of Bt-transgenic cotton line 310 were tested with cotton bollworm larvae(Helicoverpa armigera Hübner)in different growing stages. Young larvae rearing on excised leaves, squares and bolls from Bt-transgenic plant in various growing stages showed a significant inhibition of feeding. The toxic response of larvae feeding on young leaves, small to median squares was higher than that on large squares and bolls.The toxicity of Bt-transgenic plant was higher in the early growing stage and declined gradually in advance of growth and showed less toxic in motoring the plant. The weight of larvae and pupa feeding on Bt-transgenic plant was 30%￣50% less as comparing with CK. The egg production of moth emerging from Bt-transgenic plant was 50%￣70% less than that of the moth on the normal cotton plant.