【摘要】 目的研究醉鱼草(Buddleia lindleyana)内生真菌LL3026(Colletotrichum sp.)发酵液的杀螺作用、活性部位及其热稳定性和光照稳定性。方法采用烧杯浸杀法,观察不同时间、不同浓度LL3026发酵液醇浸膏水溶液对湖北钉螺的杀灭作用,同时设1mg/L氯硝柳胺水溶液和去氯离子水为对照。采用溶剂系统分离法分离LL3026发酵液的不同极性部位,并比较各极性部位的杀螺活性。该菌发酵液醇浸膏水溶液于不同温度(30～100℃)、不同时间(30～150min)处理后,进行杀螺试验,检测其热稳定性。在25℃、不同光照强度(分别照射1～9d)条件下,测定其光照稳定性。结果施药后24、48和72h的半数致死浓度(LC50)分别为50.11、3.43和1.55mg/L。分离LL3026发酵液,获得石油醚、乙醚、乙酸乙酯、正丁醇和水相等不同极性部位,其低极性部位的乙醚相杀螺效果最好,24、48和72h杀螺率均为100%。在80℃加热120min后,发酵液活性物质热稳定性好,杀螺率为100%。3600lx强度光照9d的发酵液的杀螺活性较强,其48h杀螺率为86.7%。结论醉鱼草内生真菌LL3026具有较好的杀螺活性。更多还原

【Abstract】 Objective To research the molluscicidal effect, active components, thermal stability and light stab-ility of endophyte LL3026 (Colletotrichum sp.) from Buddleia lindleyana. Methods The molluscicidal effect of LL3026 against Oncomelania hupensis was determined as referring to the WHO guidelines for laboratory molluscicidal test, and the control experiments were performed with 1 mg/L niclosamide or dechlorinated tap water. The active components from LL3026 were extracted by different polar solvents. The thermal stability and light stability of its extracellular moiety was examined at different temperature (30-100 ℃), different time (30-150 min) and different illumination time (1-9 d). Results Immersion test showed that the LC50 values for the LL3026 broth were 50.11, 3.43, and 1.55 mg/L for 24, 48, and 72 h, respectively. The ether extract of LL3026 broth showed the best molluscicidal activity compared with other fractions. Treated with 25 mg/L ether extract for 24, 48, and 72 h, the mortality of O. hupensis was 100%. The molluscicidal activity of LL3026 broth had no change at 80 ℃ for 120 min, and the snail mortality was 100%. A 48-h exposure to LL3026 broth which placed in an artificial climate box with 3 600 lx illumination for 9 d resulted in 86.7% snail mortality. Conclusion The fractions extracted from endophyte LL3026 isolated from B. lindleyana shows molluscicidal effect to O. hupensis.更多还原