薇甘菊杀线虫活性成分及其对番茄生长的影响

Nematicidal constituents of Mikania micrantha against Meloidogyne incognita Chitwood and their effects on growth of tomatoes

采用活性追踪法,从外来入侵杂草薇甘菊中提取到两种活性化合物——薇甘菊内酯和间-甲氧基苯甲酸。以南方根结线虫为测试对象,测试了两种化合物的杀线虫活性和卵囊孵化抑制率。结果表明,两种化合物具有中等强度的杀线虫活性,其中薇甘菊内酯活性较高,药后48 h的致死中浓度(LC50)为57.75 mg/L,药后6 d的抑制中浓度(IC50)为415.87 mg/L。另外,测试了两种化合物对寄主植物番茄生长、根系活力和叶片的超氧化物歧化酶(SOD)酶活的影响,结果表明两种化合物对番茄生长没有明显影响,但是可以显著减少根结线虫的侵染。根系活力和SOD酶活结果进一步证明了两种化合物抑制线虫侵染的活性。

Two compounds, mikanolide and m-methoxy benzoic acid, have been isolated from leaves of Mikania micrantha H. B. K. with method of bioactivity-guided fractionation. Nematode mortality and hatching inhibition rate were evaluated against Meloidogyne incognita. The results showed that two compounds possessed nematicidal activity and mikanolide had higher activity than m-methoxy benzoic acid. Median lethal concentration（LC50） and median inhibitory concentration（IC50） of mikanolide were 57.75 mg/L（at 48 h） and 415.87 mg/L（at 6 d）, respectively. Their effects on growth,root activity, and superoxide dismutase（SOD） enzyme activity of tomato were tested. The results indicated that both compounds had no effect on the growth of tomato but could reduce the infection of root-knot nematode. The results of root activity and SOD enzyme activity demonstrated further that both compounds could inhibit the action of nematode infection.The significance of this study was that two compounds may play a role in reducing the populations of root-knot nematode.