转基因白桦抗性等级划分及其对幼虫中肠的影响

利用39个转基因白桦无性系和对照值株分别对舞毒蛾幼虫进行了抗虫性测定，结果死亡率75％上的高抗无性系占15．38％，死亡率在41％～75％的中抗无性系占46．15％，死亡率15％～40％的低抗无性系20．51％，死亡率15％以下的无性系占17．95％。通过转基因白桦叶片饲喂舞毒蛾幼虫，取食90h后中肠受到坏，取食量开始明显减少；144h取食量后受到严重影响，中肠内食物与对照相比明显减少，证明转基因白桦叶片的毒素可以影响和破坏舞毒蛾幼虫中肠，降低其取食量，从而达到抑制害虫保护林木的目的。

Class Division of Resistance to Lymantria dispar for Transgene Betula platyphylla and Its Effect on Larvae Midgut

The resistances to Lymantria dispar for 39 transgene clones and the control of Betula platyphylla were determined. The result showed that the highest resistant clones with the mortality more than 75% accounted for 15.38%, the middle level resistant clones with mortality of 41%~75% accounted for 46.1%, the lower resistant clones with mortality of 15%~40% accounted for 21.51%, clones with mortality less than 15% accounted for 17.95%. For larvae of Lymantria dispar fed by leaves of transgene Betula platyphylla, the amount feeding began decreasing obviously and midgut was destroyed after 90 h, and the feeding was influenced severely and the food in the midgut decreased evidently compared to the control after 144 h. It proved that the toxin of leaves of transgene B. platyphylla could affect and destroy midgut of larvae, and decrease the feeding amount, thereby the pest could be restrained and forests could be protected.