中文摘要：

采用微量点滴法和载毒叶片饲喂法测定39种药用植物乙醇提取物对粘虫3龄幼虫的触杀、胃毒以及拒食活性.结果表明,供试样品在50 mg·mL^-1浓度下均无明显的触杀或胃毒作用,但卡瓦胡椒和川陈皮对试虫有一定的拒食活性,其中卡瓦胡椒24 h拒食中浓（AFC50）为4.12 mg·mL^-1,48 h为9.12 mg·mL^-1.采用抑制菌丝生长速率法和抑制孢子萌发法测定离体杀菌活性的结果表明,供试样品在2 mg·mL^-1浓度下,卡瓦胡椒和厚朴对供试病原菌均有较强抑制作用.毒力测定结果表明,卡瓦胡椒对玉米大斑病菌、番茄灰霉病菌、小麦根腐病菌、油菜菌核病菌4种病原真菌菌丝生长抑制的有效中浓（EC50）分别为108、258、290、205 mg·L^-1,厚朴分别为208、331、345、408 mg·L^-1;卡瓦胡椒对玉米大斑病菌、玉米小斑病菌、烟草赤星病菌3种病原真菌抑制孢子萌发的有效中浓（EC50）分别为155、195、268 mg·L^-1,厚朴则分别为151、242、241 mg·L^-1.根据以上结果,我们认为卡瓦胡椒和厚朴的乙醇提取物具有较高的杀菌活性,其有效成分值得进一步研究.

英文摘要：

The stomach toxicities ,contact toxicity and anti-feeding activities of the extracts of thirty medicinal plants by ethanol to three-instar Mythirnna separata larvae were investigated by micro titration and extract-carrying leaf feeding,which showed that the extracts presented no significant stomach or contact toxicity with their concentration lower than 50 mg ·mL^-1 and the extracts of Piper rnethysticurn and Citrus reticulata presented anti-feeding activity to a certain extent and the 24-and 48-hour AFC50 of Piper rnethysticum extract were 4. 12 mg ·mL^-1 and 9.12 mg ·mL^-1 ,respectively. The in vitro fungicidal activities of the extracts were examined in terms of inhibition rate in hypha growth and spore germination inhibition, which showed that the extracts of Piper methysticum and Magnolia officinalis presented relatively strong inhibitory effect on the tested pathogens with their concentrations below 2 mg ·mL^-1. Toxicity determination indicated that against Exerohilum turcicum,Botrytis cinerea, t3ipolaris sorokiniana and Selerotinia sci erotiorurn,the EC50 of Piper rnethysticurn extract were separately 108 mg ·mL^-1,258 mg ·mL^-1 and 290 mg ·mL^-1 and 205 mg ·mL^-1 and the EC50 of Magnolia officinalis extract were separately 208 mg ·mL^-1, 331 mg ·mL^-1 and 345 mg·mL^-1 and 408 mg ·mL^-1;the EC50 of Piper methysticum extract to inhibit the spore germinations of Exerohilum turcicum,Bipolaris maydis and Alternaria longipes were separately 155 mg·mL^-1,195 mg·mL^-1 and 268 mg ·mL^-1 and the EC50 of Magnolia officinalis extract to inhibit the spore germination of these pathogens separately 151 mg ·mL^-1,242 mg ·mL^-1 and 241 mg ·mL^-1. According to the above results,Piper methysticum and Magnolia officinalis extracts by ethanol were considered to have high fungicidal activities and their active ingredients were worth studying.