| 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. |
