Preliminary Studies On Isolation And Application Of Nematicidal Constituents From Soybean Hull

Plant-parasitic nematodes had become an important kind of pathogenyt and it is a problem for agriculture and forestry now.All over the world want to find some efficient and environment friendly means to control it. More and more plants were found to have nematicidal activity.This experiment extracted and purificated the nematicidal fractions form the soybean hull and studied the nematicidal activity of soybean hull and the mechanism by choosing the abundant byproduct of soybean as material.The results are as follows:1. Extracting flavonoids by different solvents , the extractive ratio was highest by 75% ethanol,it was 5.60%. and its nematicidal activity was strongest. Choosed the ethanol as solvent and did orthogonal plan for 4 facters which could effect the extractive ratio.The optimium technics was 70℃, 10:1 of 80% ethanol to soybean hull, heating and refluxing for 24 hours. The extractive ratio of optimium technics could be 8.58% and it was higher than Hypo-optimal technics significantly.2. Preliminary extracted the fractions of nematicidal activity by liquid-liquid. There were most flavonoids form soybean hull in the four fractions such as chloroform, ethyl acetate,n-butanol and water.N-butanol had most,the revised mortality were above 50% after 24 hours ,48 hours and72 hours. Ulteriorly extracted the fractions of nematicidal activity by column chromatography and TLC and amalgamated the Rf of the sample of n-butanol into 8 fractions.Fraction 2 and fraction7 had high nematicidal effect, the revised mortality were above 50% after 24 hours,48 hours and72 hours.3. Study the mechanism of fraction 2 and fraction7, the results indicated that: it could inhibit the protein and sugar and them were lower than CK evidently.The Specific activity of GST were lower than CK evidently after 24 hours and 48 hours. The specific activity of CAT were lower than CK not evidently after 24 hours but lower than CK evidently after 48 hours. It showed:the nematicidal activity of fraction 2 and fraction7 could baffle it's metabolism and unbalance their oxidation and antioxygenation and make them to die.And the nematicidal activity may effect the cuticle of nematodes, make the substance of nematodes extravasating,it could make them to die too. 4. Choosed the optimium condition was soybean hull condensate(15%),95% of ethanol(65%),xylene(10%) and of OP-10(10%). The nematicidal result saied:the 200 times was best in room and the 100 times was best in land. Did some detection for the EC and the result saied:the EC accords with the pesticide.