Studies On Bioactivity Of Polygonum Perfoliatum L. Against Panonychus Citr McGregor

45 species of plants collected from the northeast of Guangxi zhuang autonomous region were extracted with methanol. Acarocidal activities of these extracts against Panonychus citri McGregor were measureed by leaf-dip method. According to the Acarocidal activity, Polygonum pertoliatum L., which had high contact activity , was selected to be further investigated for active ingredients. And the extract was separated by solid-liquid distribution and purified through column chromatograghy. Primary mechanism was investigated through the change of several enzymes.The contact activities of 52 methanol extracts of 45 plants against Panonychus citri McGregor were tested in laboratory. Results showed that at a concentration of 10mg/mL, the extracts with higher activity(corrected mortality rate >90%) at 24h after treatment were that of Ginkgo biloba L., Stephania kwangsiensis Lo., Millettia pachycarpa Benth., Lycoris radiata Herb., Coptis chinensis Franch., Phellodendron amurense Rupr., Amorphophallus rivieri Durieu, Caesalpinia minax Hance, Trachelospermum jasminoides(Lindl.)Lem., Dichroa febrifuga Lour., Senecio scandens Buch.-Ham. ex D.DON, Microsorium fortunei(Moore)Ching, Mentha haplocalyx Brig., Mallotus repandus (Willd.) Muell. Arg., Lysimachia foenumgraecum Hance, Houttuynia cordata Thunb., Polygonum perfoliatum Linn., Milletia nitida Benth; extracts with moderate activity(corrected mortality rate of 60%⁹0%)were that of Mahonia fortunei (Lindl.)Fedde ,Ranunculus cantoniensis Bunge, Viburnum dilatatum Thunb., Ponicirus trifoliate (Linn.) Raf., Didymocarpus eburneus(Hance)Levl., Crotalaria ferruginea Grah ex Benth., Agrimonia pilosa Ledeb., Aspidistra retusa K.Y.Lang et S.Z.Huang, Blechnum orientale L., Gardenia jasminoides Ellis, Sapium chihsinianum S.Lee, Vitex negundo L., Duchesnea indica(Andrews) Focke, Cupressus funebris Endl., Eriobotrya japonica(Thunb.) Lindl; contact activities of the others were lower, with corrected mortality rate below 60%.Contact toxicities of 8 plant extracts were further determined. The extracts from leaves of Ginkgo biloba L. had the highest contact toxicities against Panonychus citri McGregor, with a LC₅₀ value of 1.9248mg/mL. Relative toxicities of the eight plant extracts, in order from highest to lowest, were: leaves...