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Studies On Bioactivity Of Schima Superba Gardn. Et Champ. Against Vegetable Pests

Posted on:2009-06-18Degree:MasterType:Thesis
Country:ChinaCandidate:Z Y DengFull Text:PDF
GTID:2143360245959638Subject:Conservation and Utilization of Wild Fauna and Flora
Abstract/Summary:PDF Full Text Request
It is a focus on the study of botanical pesticides to find bio-active natural products from plants, it is very interesting to isolate these compounds and to make use of them as new agrochemicals or leading structures for new agrochemicals. For the purpose of exploiting insecticidal plants in China, extracting and isolating active ingredients from them, insecticidal activity of 60 species of plants collected from Fangchenggang city and the northeast of Guangxi zhuang autonomous region against Plutella xylostella(L.) and Spodoptera litura Fabricius was determined. On the basis of activity screening, Schima superba Garnd. et Champ., which had the the highest bioactivities, was chosen for further investigation. Insecticidal activity of methanol extracts from different parts of Schima superba Garnd. et Champ. against Plutella xylostella(L.) and Pieries rapae L., action mode against Plutella xylostella(L.) and Pieries rapae L., primary isolation of active ingredients, potted trial and field control efficiency of pesticide preparations of Schima superba Garnd. et Champ. were studied in this paper. The results are as follows.1. The results of bioactivity test indicated that the methanol extracts from 5 species of plants had high poisonous activity against 3rd instar of Plutella xylostella(L.), and the activity of the methanol extract of Schima superba Garnd. et Champ. and Camellia oleifera Abel. was the best, with the 72h corrected mortality against 3rd instar of Plutella xylostella(L.) of 100% and 98.50% at 10g/L, respectively; the 72h corrected mortality of Atropa belladonna was 84.60%; Vernicia fordii Hemsl and Pithecellobium clypearia. had also poisonous activity, the 72h corrected mortality was 66.70% and 59.00%, respectively.2. Insecticidal activities of methanol extracts from different parts of Schima superba Garnd. et Champ. against Plutella xylostella(L.) and Pieries rapae L. were tested. The results showed that bioactivity of the extract from barks and leaves were the highest, and the bioactivity of extract from fruits was the lowest. The 72h corrected mortality of methanol extracts from barks, leaves and fruits against 3rd instar of Plutella xylostella(L.) were 98.33%, 96.74% and 25.00% at 10g/L, respectively; the 96h corrected mortality against 3rd instar of Pieries rapae L. were 100%, 100% and 23.33%, respectively; their 48h antifeedant rates against 3rd instar of Plutella xylostella(L.) were 94.78%, 94.01% and 25.56% at the concentration of 10g/L, respectively; their 48h antifeedant rates against 3rd instar of Pieries rapae L. were 100%, 78.22% and 5.37% at the concentration of 2g/L, respectively.3. The results showed that the extracts from barks and leaves exhibited mainly antifeedant activity and growth inhibition against Plutella xylostella(L.) and Pieries rapae L.. In addition, they possessed certain contact poison effect, but no stomach action. The 48h antifeedant rates of the methanol extracts from barks and leaves against 3rd instar of Plutella xylostella(L.) were 92.14% and 90.22%, respectively, at the concentration of 9g/L; their 48h antifeedant rates against 3rd instar of Pieries rapae L. were 93.16% and 71.19%, respectively, at the concentration of 1g/L. The results also showed that the methanol extract from barks and leaves of Schima superba Gardn. et Champ. had a relatively high growth inhibition effect on Plutella xylostella(L.) and Pieries rapae L., and their 24h growth inhibition rates against 3rd instar of Plutella xylostella(L.) were 92.35% and 91.28%, respectively, at the concentration of 8g/L; their 24h growth inhibition rates against 3rd instar of Pieries rapae L. were 94.52% and 89.73%, respectively, at the concentration of 2g/L. The methanol extracts from barks and leaves of Schima superba possessed certain contact poison effect, their 72h cerrected mortality against 3rd instar of Plutella xylostella(L.) were 32.30% and 17.94%, respectively, at the concentration of 10g/L; their 72h cerrected mortality against 3rd instar of Pieries rapae L. were 36.67% and 10.00%, respectively.4. Antifeedant activities of methanol extracts from Schima superba Garnd. et Champ. against 3rd instar of Pieries rapae L. was higher than that against 3rd instar of Plutella xylostella(L.). The 48h AFC50 of the methanol extract from barks against 3rd instar of Plutella xylostella(L.) and Pieries rapae L. were 1.5519g/L and 0.1488g/L, respectively. The 48h AFC50 of the methanol extracts from leaves against 3rd instar of Plutella xylostella(L.) and Pieries rapae L. were 1.6523g/L and 0.3638 g/L, respectively.5. Methanol extract from barks of Schima superba Garnd. et Champ. were isolated by means of phytochemistry combined with bioassay. Methanol extract were continuously extracted by petroleum ether and n-butanol, and n-butanol extract possessed the highest activities, with the 24h and 48h antifeedant rates against 4th instar of Pieries rapae L. being 99.08% and 96.44% at the concentration of 1g/L, respectively. Petroleum ether extract and distilled water extract had no antifeedant activities against 4th instar of Pieries rapae L. The n-butanol extract was isolated by silica gel column chromatography. The part of 11-10 had the highest antifeedant activity, with the 24h and 48h antifeedant rates against 3rd instar of Plutella xylostella(L.) being 91.82% and 94.11% at the concentration of 1.5g/L, and the 48h antifeedant rates of the others had no more than 20%.6. The 13C-NMR data of active part 11-10 were analyzed, and showed that the active part contained compounds of glycosides. By analyzing correlative literatures, the active ingredients of barks of Schima superba Garnd. et Champ. were preliminarily identified as compounds of glycosides.7. The methanol extract from barks of Schima superba Gardn. et Champ. was used as material to make insecticide preparation. 20% AS of Schima superba Garnd. et Champ. had high control efficacy. The results of potted trial indicated that the control efficacy of 5, 10 and 20 times solution against Plutella xylostella(L.) were 100%, 92.67% and 86.67% after 3d, the rates of leaf protection were 96.97%, 73.81% and 42.94%, respectively. The results of field control indicated that the control efficacy of 5, 10 and 20 times solution against Plutella xylostella(L.) were 98.37%, 92.38% and 87.71% after 7d.
Keywords/Search Tags:Schima superba Garnd. et Champ., Bioactivity, Active ingredients, Plutella xylostella(L.), Pieries rapae L.
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