河朔荛花农药生物活性初探

1材料与方法 1．1材料①植物。河朔荛花2006年夏季采于延安大学文汇山。取其花于阴凉处干燥，粉碎后备用。②昆虫。粘虫3龄幼虫．室内人工饲养，由西北农林科技大学农药研究所提供，饲养条件为（25±1）℃；蚜虫采于陕西延安苹果树上。③病菌。小麦赤霉病菌、苹果炭疽病菌、西瓜枯萎病菌、番茄早疫病菌、马铃薯干腐病菌，均由西北农林科技大学农药研究所微生物实验室提供。④试剂。甲醇、丙酮、氯仿、乙酸乙酯、石油醚等溶剂均为分析纯，西安化学试剂厂生产。

A Preliminary Study on Biological Activity of Wikstroemia chamaedaphne Meissn

Objective] The insecticidal and antibacterial bioactivity of Wikstroemia chamaedaphne Meissn were screened and bioactive substances in it were separated and purified. Method]The Wikstroemia chamaedaphne Meissn was conducted ultrasonic extraction in petroleum ether, ethyl acetate and methanol. The insecticidal activity of Wikstroemia chamaedaphne Meissn to Mythimna separata walker and aphid were determined. The antibacterial activity of Wikstroemia chamaedaphne Meissn to Fusarium graminearu, Glomerella cingulata, F.oxysporium f.sp niveum, Alternaria solani and Fusarium oxysporium were also determined. The bioactivity-guided methods such as opencolumn chromatography and Pre-HPLC method were used to separate active components in petroleum ether extract from Wikstroemia chamaedaphne Meissn. Result] When the concentration was 500 mg/L, 3 kinds of extracts from Wikstroemia chamaedaphne Meissn didn't show obvious antibacterial bioactivity to 5 kinds of test samples. When the concentration was 5%, petroleum ether extract show certain topical toxicity to aphids. The ethyl acetate extract showed certain antifeedant activity to 3rd instar Larvae of Mythimna separata Walker. The fraction F4 of petroleum ether extract possessed highest topical toxicity to aphids and the lethality was 60.00%.Conclusion] Wikstroemia chamaedaphne Meissn contained many insecticidal constituents whose active parts and mechanism were needed further researches.