5,7,4-三羟基黄酮等生物源化合物对菜青虫幼虫生长发育的影响

为了研究生物源化合物对菜青虫幼虫Pieris rapae（L.）生长发育的影响,选用5,7,4＇-三羟基黄酮、槲皮素、芦丁、5-甲氧基水杨酸和曲酸5种化合物,以触杀和摄食毒力法进行了生物活性测定.结果表明,5,7,4＇-三羟基黄酮和槲皮素对菜青虫幼虫生长发育具有明显的影响,浸渍法处理后72 h,两种化合物对试虫致死LC50值分别为0.226和0.951g/L;叶片药膜法处理后72 h,LC50值分别为0.062和2.420 g/L.结果还表明,采用叶片药膜法,当5,7,4＇-三羟基黄酮的浓度高于0.200g/L时,所有试虫均不能正常化蛹;采用浸渍法,用5,7,4＇-三羟基黄酮、槲皮素、芦丁、5-甲氧基水杨酸和曲酸处理的菜青虫5龄幼虫体重与对照相比增长量明显降低.离体试验结果显示,5,7,4＇-三羟基黄酮和槲皮素对菜青虫酚氧化酶（phenoloxidase,EC.1.14.18.1）具有明显的抑制作用,抑制中浓度（IC50）分别为25.65和43.94mg/L.

Effect of natural occurring compounds 5,7,4''''-trihydroxyflavone etc. on growth of Pieris rapae (L.) larva

Some natural occurring compounds, 5,7,4'-trihydroxyflavone, quercetin, rutin, 5-methoxysalicylic acid and kojic acid, were selected to investigate the effects on the growth of Pieris rapae larvae. Dipping methods and ingestion methods were used and the results showed that the LC_ 50 value of the chemicals against the tested larvae were 0.226 and 0.951g/L at 72 hours after treatment with dipping methods for 5,7,4'-trihydroxyflavone and quercetin, respectively, and 0.062 and 2.420g/L with ingestion methods, respectively. All of the tested larvae couldn't pupated as 5,7,4'-trihydroxyflavone beyond 0.200g/L with ingestion methods, and the increased amount of body weight of the 5th instar larvae, which were dipped in the solution of 5,7,4'-trihydroxyflavone, quercetin, rutin, 5-methoxysalicylic acid or kojic acid, were decreased obviously compared with the control. The vitro investigation showed that 5,7,4'-trihydroxyflavone and quercetin could inhibit the activity of phenoloxidase from the larvae, and the IC_ 50 were 25.65 and 43.94mg/L, respectively.