夹竹桃皂甙对福寿螺的毒杀效果及其对水稻幼苗的影响

室内条件下研究了夹竹桃皂甙对福寿螺的杀灭效果及其对水稻幼苗的影响。结果表明，福寿螺的致死率随着皂甙浓度的增加和处理时间的延长而显著上升，其中50mg/L 浓度皂甙处理48h的致死率达100%，与0.156g/L氯硝柳胺水溶液的灭螺效果相当。皂甙对福寿螺的杀灭效果与福寿螺的大小有关。皂甙对壳高h＜10 mm的福寿螺的杀螺效果最好, 而对20≤h<30 mm的杀螺效果最差。水稻幼苗的存活率随着皂甙浓度的增加而显著增加，且低浓度皂甙处理24h也具有较高的值。此外，采用水培方法研究了皂甙对水稻幼苗鲜重的影响。高浓度(≥40 mg/L)的皂甙处理7d显著地抑制了水稻幼苗根部和地上部分的鲜重，其中对根部的影响大于地上部分。当处理时间延长到14d时，皂甙对水稻幼苗鲜重的抑制作用逐渐减弱,仅50mg/L 皂甙处理对根部鲜重有显著地抑制。而在氯硝柳胺水溶液处理下，水稻幼苗停止生长。综合结果表明夹竹桃皂甙是一种环境友好且能高效防治福寿螺的灭螺剂。

Molluscicidal efficacy of Nerium indicum cardiac glycosides on Pomacea canaliculata and its effects on rice seedling

P.canaliculata is now a major rice pest in Asia.For snail management,it is therefore imperative to develop an effective and practical method which is relatively safe to the non-target organisms and to the environment.Recently much attention has been given to study the molluscicides from plants,because they might provide effective,locally produced,biodegradable and environment-friendly approach for controlling snail.In this study,cardiac glycosides from the fresh leaves of N.indicum were isolated and 100 g f...