Screening For Agriculturally Useful Activity Of A Kind Of Leguminous Plant And Study On It’s Molluscicidal Active Substance Against Pomacea Canaliculata

Screening for agriculturally useful activity of a kind of Leguminous plant and the molluscicidal active substances against Pomacea canaliculata were studied in this thesis.The main results are as follows:(1)The agricultural activities of the 3 kinds of extracts by methanol, ethyl acetate and petroleum ether from root and stem of KGT were measured.The results of inhibiting the mycelial growth rate showed that, the methanol extract of KGT root exhibited obvious fungicidal activity against the mycelial growth of Rhizoctonia solaniat lmg/ml concentration, and the inhibitory rate was 67.5%.The EC50 value against the mycelial growth of R. solani was 430.51μg/ml.The results of the insecticidal activity tests showed that, all KGT extracts from root and stem had no lethal activity on the tested insect larvaes including Ostrinia nubilalis, Mythimna separate and Ectropis oblique at the concentration of 10mg/ml.The tested results of molluscicidal activity of KGT extracts showed that, the methanol extracts of KGT root exhibited strong lethal activity on P. canaliculata, and the value of LC50 on P. canaliculata whose shell diameter was 15mm was 26.92μg/ml and 4.77μg/ml with treated 48h and 72h, respectively, the value of LC50 on P. canaliculata whose shell diameter was 25mm was 59.2μg/ml and 10.05μg/ml with treated 48h and 72h, respectively.(2) The action mode of the methanol extracts of KGT root on the P. canaliculata were studied, the results showed that, the methanol extracts of KGT root had contact toxicity on the P. canaliculata, no stomach toxicity.Under the high concentration, the methanol extracts of KGT root had antifeedant activity and ovicidal action on the P. canaliculata.(3)Using macroporous resin, silica gel column chromatography and high performance liquid chromatography preparation, the molluscicidal active substances of the methanol extract of KGT root were studied. The results showed that, the active fractions of HPD300 macroporous resin adsorption and analysis had the best effect; using ethyl acetate: chloroform=1:3(V/V) as the solvent system, the materials of analytical solution of macroporous resin was isolated by silica gel column chromatography, the 22 fractions obtained. Activity tracking showed that, the fraction H1, H2, H3 and H4 exhibited strong lethal activity on P. canaliculata. the largest amount of fraction H3 and H4 was further separated into 2 single compounds H3-3 and H4-2 by HPLC. The structure were identified as PedunsaponinC and Pedunsaponin A, respectively.