山石榴果实提取物对小菜蛾的拒食作用

以室温冷浸法，用石油醚、乙酸乙酯和甲醇等溶剂对山石榴Catunaregam spinosa果实进行提取，其提取率分别为0．44％、1．80％和17．10％．拒食活性测定结果表明：在10mg／mL的质量浓度下，甲醇提取物对小菜蛾Plutella xylostella幼虫的拒食活性最高，24h非选择性拒食率达82．49％．对甲醇提取物进行活性成分分离，初步确定活性成分主要存在于正丁醇萃取物和甲醇／水（体积比为10／3）的沉淀物中，质量浓度为10mg／mL时，正丁醇萃取物和甲醇／水沉淀物对小菜蛾幼虫24h拒食率分别为91．24％和96．77％．

Antifeedant activity of Catunaregam spinosa fruit extracts against Plutella xylostella

The fruit extracts of Catunaregam spinosa were used to tested for antifeedant activity against the larvae of Plutella xylostella in the study.The powdered fruit was extracted with petroleum ether,ethyl acetate and methanol,and the extract rates were 0.44%,1.80% and 17.10%,respectively.The methanol extract showed more antifeedant activity against the larvae of Plutella xylostella than the petroleum ether extract and ethyl acetate extract,and the antifeedant rate of the methanol extract in 24 h after treatment in the no-choice bioassay reached 82.49% at the concentration of 10 mg/mL.The active ingredients of the methanol extract were separated preliminarily.The results showed that the antifeedant components were mainly in the precipitate in the methanol /water partition(V/V=10/3),and in the n-butyl alcohol fraction after the methanol extract was partitioned in n-butyl alcohol and water.Antifeedant rates of the precipitate and the n-butyl alcohol fraction in 24 h after treatment were 96.77% and 91.24% at the concentration of 10 mg/mL,respectively.