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Test Of Biological Activities And Isolation Of Effective Components For Artemisia Ordosica K. Against Mythimna Separata (Walker)

Posted on:2008-12-29Degree:MasterType:Thesis
Country:ChinaCandidate:C R LiuFull Text:PDF
GTID:2143360215468192Subject:Agricultural Entomology and Pest Control
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The overground parts of Artemisia ordosica Kraschen, belonging to Compositae, were extracted by different methods and solvents. Biological activities of crude extracts and fractions against Mythimna separata Walker were tested,at the same time, the effective components of ethyl acetate of Artemisia ordosica Kraschen were separated.The results were listed as follows:1 The acetone extracts of 16 plant species were tested for their biological activities against Mythimna separata Walker. The results showed that the anti-feeding rates of 10 plant species had over 50% after 48h treatment; emendation mortality rates of 7 plant species had over 50% with diping methods after 72h treatment, the acetone extracts of Artemisia ordosica Kraschen possessed the highest activities, the anti-feeding rate and emendation mortality rate were 97.83%and 80%.2 Three methods and five solvents were used to extract overground parts of Artemisia ordosica Kraschen, 15 extracts were acquired .The results indicated that Sohxlet was the most effective extraction method, the extract rate with ethyl acetate was 17.97%, then warm soaking was 11.41 % , the cold soaking,the last method was 5.92 % respectively . The extract rates with the same extraction methods from heigh to low were ethyl acetate, acetone, chloroform, n-hexane, petroleumether.3 Bioactivity experiments were conducted with Artemisia ordosica Kraschen extracts used Mythimna separata Walker as a test species. The results showed that 15 extracts all had biological activities against Mythimna separata Walker, the activities of different ectracts had distinct difference. Ethyl acetate extracts of Sohxlet of Artemisia ordosica Kraschen showed the highest biological activities mainly in anti-feeding,contacting and inhibiting growth activities, while weak stomach toxicity effect: In anti-feeding test , the AFC50 was 8.4mg/ml. It showed a highest contact efficacy against the Mythimna separata Walker, the 72h emendation mortality with a dipping treatment was 89.29%.Ethyl acetate extracts also possessed significant inhibition growth activities, caused 91.78%and 86.32% inhibition after 24h and 48h treatment, respectively, average pupa weight was 169.1mg , and pupation rate was only 43.33%, the speed of growth and development was delayed . Other extracts also showed biological activity.4 Ethyl acetate extracts of Sohxlet of Artemisia ordosica Kraschen were successively separated by fluid-fluid distribution, the extracts rates were petroleumether>chloroform >ethyl acetate>n-butanol>water. Bioactivity experiments by using anti-feeding and direct contact methods, petroleumether extract showed the significant activity, anti-feeding rate was 91.84% after 24h treatment, mortality rate was 86.67% after 72h treatment, the chloroform extract also possessed higher activity, anti-feeding rate, mortality rate were 77.05% and 66.33% after 24h and 72h treatment respectively.5 The petroleumether extracts were isolated and purified by column chromatography and thin-layer chromatography (TLC). Thirteen fractions were got after combination, through direction of bio-assay, the results showed that the activity components of anti-feeding were concentrated in fractions L3, L4, L5, the anti-feeding rates had all over 89%, fraction L4 had the heighest activity, after TLC, the results showed that L4 had two components, L3 had one component, the Rf limit of major component was 0.56, which got to first base for the identification of components.Based on the result, extraction of plant material and activity of the extraction of the Artemisia ordosica Kraschen, the separation and purification of plant material, the mechanism, the problem and the foreground were discussed in this paper.
Keywords/Search Tags:Botanical insecticide, Artemisia ordosica Kraschen, extraction, Mythimna separata, insecticidal activity
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