Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture of the PRC and Zhejiang Province, Zhejiang University, Hangzhou 310058, China.
Sci Total Environ. 2023 Jun 20;878:162983. doi: 10.1016/j.scitotenv.2023.162983. Epub 2023 Mar 22.
Dufulin (DFL), a plant antiviral agent synthesized in China, has been widely used to control viral diseases in rice, tobacco, tomato, and other crops. However, its fate in flooded anaerobic soils, which is essential for environmental risk assessment, remains unknown. Using the C tracer technique, the fate of C-labeled DFL isomers in flooded anaerobic soils was systematically investigated in this study. Over the 100-day incubation, a small part of C-DFL enantiomer was mineralized to CO (< 10.44 %) or entered the surface water phase (< 6.69 %), with most of the C (> 80.40 %) remaining in the subsoil. The residues in all tested soils were gradually converted from extractable residues (ERs) to nonextractable residues (NERs). At the end of incubation, the fraction of C-NERs reached 5.38-23.77 %. The half-life (t) of the DFL parent in soil is relatively long under submerged anaerobic conditions, especially in Fluvo-aquic soil, up to 277.26-315.07 days, which exceeds the risk threshold recommended by the Stockholm Convention (< 180 days). Soil type and microbial activity influenced the fate of DFL in flooded soils and microbial analysis showed that 2.0 mg kg DFL had no obvious impact on soil bacterial richness and function. Pseudomonas spp. was estimated to be a potentially efficient degrading genus for DFL. No enantioselective behaviors were detected in this study. This research provides a theoretical basis for evaluating the environmental impact and ecological safety of DFL application.
杜氟林（DFL）是一种中国合成的植物抗病毒剂，已广泛用于控制水稻、烟草、番茄等作物的病毒病。然而，其在淹水厌氧土壤中的归宿对于环境风险评估至关重要，目前尚不清楚。本研究采用 C 示踪技术系统研究了 C 标记 DFL 对映体在淹水厌氧土壤中的归趋。在 100 天的培养过程中，一小部分 C-DFL 对映体被矿化为 CO（<10.44%）或进入地表水相（<6.69%），大部分 C（>80.40%）仍留在亚表层。所有测试土壤中的残留物逐渐从可提取残留物（ERs）转化为不可提取残留物（NERs）。在培养结束时，C-NERs 的分数达到 5.38-23.77%。在淹没的厌氧条件下，DFL 母体在土壤中的半衰期（t）相对较长，特别是在 Fluvo-aquic 土壤中，长达 277.26-315.07 天，超过了《斯德哥尔摩公约》建议的风险阈值（<180 天）。土壤类型和微生物活性影响了 DFL 在淹水土壤中的归宿，微生物分析表明，2.0mgkg 的 DFL 对土壤细菌丰富度和功能没有明显影响。假单胞菌属被估计为 DFL 的一种潜在有效降解属。本研究未检测到对映体选择性行为。这项研究为评估 DFL 应用的环境影响和生态安全提供了理论依据。
