Abstract：
Guvermectin is a novel biopesticide often used as seed soaking to promote the rice yield. However, its biotoxicity and degradation behavior in soils were still not disclosed, which posed a knowledge gap to guide its rational application. Therefore, the degradation behaviors of guvermectin in four typical soils under aerobic and anaerobic conditions were investigated in the laboratory. The results showed that guvermectin was degraded fast with DT50 ranging from 0.95 to 10.10 d, and the degradation rate was higher in aerobic condition than that in anaerobic condition. Eight transformation products were screened using UPLC-QTOF/MS. The acute toxicities tests of guvermectin to Coturnix coturnix japonica and Apis mellifera were measured by biological laboratory experiments, and the acute and chronic toxicities of transformation products to Danio rerio, Daphnia magna Straus and Green algae were predicted by ECOSAR software. The results showed that guvermectin has low toxic to quail and honeybee (LD50 2000 mg a.i./kg body weight, LD50 ˃ 100 μg a.i./bee), and its transformation products were also low toxic class to Danio rerio, Daphnia magna Straus and Green algae (LC50/EC50 > 100 mg a.i./L). However, the nucleoside-like metabolites may pose a potential risk due to their similarity to genetic material, which should be concerned. The findings provided important environmental risk assessment data for the rational use of guvermectin.
摘要：
Guvermectin是一种新型的生物农药，常用于浸种以促进水稻产量。然而,其在土壤中的生物毒性和降解行为仍未披露，这就形成了一个指导其合理应用的知识鸿沟。因此,在实验室研究了四种典型土壤中古维菌素在好氧和厌氧条件下的降解行为。结果表明，格维菌素降解速度快，DT50在0.95~10.10d范围内，好氧条件下的降解率高于厌氧条件。使用UPLC-QTOF/MS筛选了八种转化产物。通过生物实验室实验，测定了古维菌素对子商品和蜜蜂的急性毒性试验。以及转化产品对Daniorerio的急性和慢性毒性，通过ECOSAR软件对大型水蚤和绿藻进行了预测。结果表明，格维菌素对鹌鹑和蜜蜂具有低毒性（LD502000mga.i./kg体重，LD50100μga.i./bee)，其转化产品对Daniorerio来说也是低毒性的，大型水蚤和绿藻（LC50/EC50>100mga.i./L）。然而,核苷类代谢物由于与遗传物质相似，可能会带来潜在的风险，这是应该关注的。研究结果为格维菌素的合理使用提供了重要的环境风险评价数据。
