南疆棉区转Bt基因棉对棉铃虫抗性表达及对节肢动物的影响

2000－2001年在新疆喀什叶城县研究了转Bt基因棉MD－80不同发育阶段对棉铃虫的抗性表达和棉田节肢动物群落。结果表明：1）转Bt基因棉棉叶对棉铃虫初孵幼虫有2个抗性高峰期5月中下旬和7月底，抗虫性分别为94．5％和83．3％，8月份抗性最低（22．7％），而河南的研究表明8月份正是第2个抗性高峰，抗虫效果高达93．8％；2）7月上旬棉株不同器官抗棉铃虫的强弱依次为：棉苞叶（96．7％），棉蕾（74．2％），花瓣（60％），棉叶（50．2％），棉铃（30％），花蕊（26．8％）；3）转Bt基因棉对不同龄期棉铃虫抗性随着龄期的增大而降低；4）节肢动物群落多样性，均匀度顺序依次为普通棉对照田（不进行任何防治，0.7706和0.1883),Bt棉药防田（使用化学农药防治害虫，0．3968和0．0931），Bt棉自控田（仅依靠自然天敌控制害虫，0．2211和0．0549），优势集中性依次为Bt棉自控田（0．9264），Bt棉药防田（0．8625），普通棉对照田（0．6881），表明普通棉对棉田的节肢动物群落最稳定，Bt棉药防田次之，Bt棉田自控田最差。

Transgenic Bt Cotton''s Expression on Cotton Bollworm''s Resistance and Effect on the Arthropod Community in the Field of South Xinjiang

From 2000-2001,various parts of transgenic Bt cotton were tested with cotton bollworm larvae at different growing stages and investigated arthropod community structure in Yecheng,Xinjiang. The results were as follows. 1) Transgenic Bt cotton showed the highest resistance to cotton bollworm at the last tendays of May and July, which were 94.5% and 83.3%,but the resistance was the lowest in August(22.7%). 2) Different organs have different resistance to larvae of cotton bollworm, which was cotton bract(96.7%)? cotton bud(74.2%)?cotton petal(60%)?cotton leaf(50.2%)?cotton boll(30%)?cotton pistil(26.8%) on the first ten days of July. 3) Elder larvae have more ability to resist Bt cotton than younger larvae. 4) The diversity and evenness index were the common cotton without controlling any pest(0.7706 and 0.1883)?the Bt cotton field which utilized pesticides to control pest(0.3968 and 0.0931)?the Bt cotton field with natural enemies to control pests(0.2211 and 0.0549). The dominate concentration were Bt cotton field with natural enemies to control pests(0.9264)? Bt cotton field which utilized pesticides to control pest (0.8625)? the common cotton field(0.6881).So the stability of arthropod in the common cotton field was better than that of the transgenic Bt cotton field.