抗性棉铃虫在转基因棉花上某些生命参数的研究

用室内转Bt基因棉叶汰选的低抗种群及同源对照种群,测定对田间不同生育期转基因抗虫棉叶及常规棉叶的反应.结果表明,抗性和敏感种群在常规棉叶上,幼虫存活率、化蛹率、幼虫历期及蛹重等指标均无显著差异,但抗性种群的每雌产卵量降低.抗性种群在转基因棉花上存活随棉花不同生育期的变化而出现差异.在7月下旬、8月下旬开始接虫的两代,第10天幼虫存活率,抗性种群比敏感种群提高;而在6月下旬开始接虫,抗性种群与敏感种群一样均不能化蛹,抗性种群化蛹率的提高仅在棉花生长后期(8月下旬开始接虫).比较敏感种群,抗性种群在转基因棉花上幼虫存活率提高,但存活幼虫生长缓慢,幼虫历期延长,蛹重明显减轻.结果表明,低水平抗性种群虽然对转基因棉花有一定适应性,但在转基因棉花上仍然生长发育不正常.

Changes of Some Life Parameters in the Resistant Bollworm[Helicoverpa armigera (Hübner)] Fed on Bt Transgenic Cotton

The responses of two populations of cotton bollworm [Helicoverpa armigera(Hubner)]with low resistance and susceptibility respectively to Bt(Gene CrylAc of Bacillus thuringiensis Berliner)transgenic cotton (Gossypium hirsutum L.)were tested and compared in laboratory.As fed on nontransgenci cotton leaves,except the lower fecundity in resistant population,all the larval survival,duration and pupal weight of both populations were similar.While fed on transgenic cotton leaves collected in late June,July and August,the survival of ten days old larvae fed in late July and August and pupation rate of the larvae fed in late August in resistant population were highter than those in susceptible population,but the development of larval survivors was significantly slower and pupal weight was significantly lower than those fed on non-transgenic cotton leaves.No pupation of larvae fed in late June was found both in resistant and susceptilble population.It was indicated that,the resistant cotton bollworm has increased its adaptation to Bt transgenic cotton,but by such low resistance ,it still cannot grow and develop normally like that feeding on nontransgenic cotton.