Reaction of Oncomelania hupensis to the allelopathic triterpene sapogenin from Nerium indicum

摘要

We has analyzed allelopathic effects of NeriuM indicum on Oncomelania hupensis through triterpene sapogenins, a potential molluscicide. The snails were exposed under six various concentrations (0, 20, 40, 60, 80, 100 mg/L) of triterpene sapogenins and five periods (1, 2, 3, 4, 5 days). The mortality of nails were positively correlated with the concentration of triterpene sapogenins and exposure time. The observation of both scanning electron microscope and transmission electron microscope proved that 40 mg/l triterpene sapogenins caused apparent damage to the structure of soft tissue, liver and intestine of O. hupensis. The activity of esterase (EST) isozyme of snail O. hupensis treated by 40 mg/L triterpene sapogenins was higher than that of the control between 24-48 h, and then decreased and disappeared after 72 h. It was implicated that the extracted triterpene sapogenin from Nerium indicum were promising for controlling the snail, which also providing the foundation for constructing plant community of oleander to control O. hupensis.