中文摘要：

为了探讨印楝素调节昆虫生长发育的细胞毒理机制，寻找杀虫作用新靶标，以含印楝素0．5、1．0、2．0、3．0、5．0mg／kg的培养基饲养黑腹果蝇幼虫，观察幼虫生长发育情况，通过荧光显微技术研究胚胎发育过程中的细胞凋亡．结果表明，印楝素处理可显著抑制黑腹果蝇幼虫的生长发育，处理后5d平均虫重由对照的1．41mg降低至1．13～0．38mg，发育历期由对照的4．50d延长至5．17—12．33d，发育抑制率为19．86％～73．05％，或形成永久性幼虫不能化蛹，最终死亡；部分幼虫虽然能化蛹，但化蛹率下降至1．67％～63．33％，均显著低于对照组的95．00％，羽化率由对照的95．00％下降至63．33％～1．67％，平均产卵数由对照的57．33下降至29．67～4．33，出现畸形成虫，个体明显变小．运用荧光显微镜观察发现，印楝素0．5mg／kg和2．0mg／kg处理能明显推迟果蝇胚胎细胞凋亡高峰期，缩短凋亡峰期的持续时期．

英文摘要：

The growth inhibition of Drosophila melanogaster was caused by azadirachtin, a botanical insecticidal limonoids component isolated from Azadirachta. It was investigated that the cell toxicological mechanism prevented insect＇s growth and a new insecticidal target was found. The larvae ofD. melanogaster fed on the diet contained 0.5, 1.0, 2.0, 3.0, 5.0 mg/kg of azadirachtin in the laboratory, and statistics proved the larvae growth. The apoptosis of D. melanogaster larvae was investigated through fluorescence microscopy. Results showed that azadirachtin under the tested 0.5, 1.0, 2.0, 3.0, 5.0 mg/kg concentration obviously inhibited the growth ofD. melanogaster larvae. After 5 d being treated with 1-5 mg/kg of azadirachtin, the average weight changed into 1.13-0.38 mg per larva, and the larval developmental period lasted 5.17-12.33 d from 1.41 mg per larva and 4.50 d in control respectively. The growth inhibition rate was 19.86%-73.05%. Some tested larvae delayed pupation, even permanently stayed in larval stage till to die. There were many malformation pupae and adults and the emergence rate of pupae emergence rate decreased to 63.33% - 1.67% while 95% in control, the eggs laid per female decreased to 29.67 - 4.33 while 57.33 in control, respectively. The results showed that apoptosis could be rapidly and reliably visualized in different living D. melanogaster embryos after treatment with 0.5 mg/kg and 2.0 mg/kg of azadirachtin using the vital dyes acridine orange by means of fluorescence microscopy. The peak of apoptosis obviously delayed and duration of apoptosis peak shortened. It is concluded that azadirachtin may inhibit the growth ofD. melanogaster by induction of apoptosis, which may be a putative mechanism of insect growth inhibition caused by azadirachtin.