Federal University of Lavras, Department of Phytopathology, Lavras, Minas Gerais, 37200-900, Brazil.
Federal University of Lavras, Department of Chemistry, Lavras, Minas Gerais, 37200-900, Brazil.
Plant Dis. 2023 Aug;107(8):2352-2358. doi: 10.1094/PDIS-05-22-1075-RE. Epub 2023 Aug 8.
The demand for new soil fumigants has increased as a result of more restrictive legislation regarding the use of pesticides. In the present study, the potent nematicidal activity of volatile organic compounds released by the leaf macerate was demonstrated. In addition, we searched in the volatilome for a molecule with potential to be developed as a new fumigant nematicide. In the greenhouse, even the lowest concentration of soursop leaf macerate tested (1.0%) as a biofumigant caused a significant ( < 0.05) reduction in infectivity and reproduction when compared with the nontreated control (0%). Forty-one compounds were identified through gas chromatography-mass spectrometry analysis, of which three (sabinene, caryophyllene oxide, and 4-ethylbenzaldehyde) were selected for studies against the nematode. Among these compounds, in in vitro trails, only 4-ethylbenzaldehyde showed nematicidal activity at 250 µg ml. The effective doses of 4-ethylbenzaldehyde predicted to kill 50 and 95% of the second-stage juvenile population after 48 h of exposure were 35 and 88 µg ml, respectively. In in vitro tests, 4-ethylbenzaldehyde at 150 µg ml reduced egg hatching to values similar ( > 0.05) to those of the commercial nematicide fluensulfone at a concentration of 200 µg ml. In plant experiments, as a soil fumigant, 4-ethylbenzaldehyde at a dose of 1 ml/liter of substrate had an effect similar ( > 0.05) to that of the commercial fumigant Dazomet (250 µg ml). Therefore, 4-ethylbenzaldehyde shows potential for development as a new nematicide.
由于有关农药使用的法规更加严格，对新型土壤熏蒸剂的需求有所增加。在本研究中，证明了由叶子浸提液释放的挥发性有机化合物具有很强的杀线虫活性。此外，我们在挥发物中寻找具有开发潜力的新熏蒸杀线虫剂的分子。在温室中，即使测试的最低浓度（1.0%）的罗望子叶浸提液作为生物熏蒸剂，与未处理的对照（0%）相比，也会显著（<0.05）降低线虫的感染力和繁殖力。通过气相色谱-质谱分析鉴定出 41 种化合物，其中 3 种（柠檬烯、石竹烯氧化物和 4-乙基苯甲醛）被选为针对线虫的研究对象。在这些化合物中，只有 4-乙基苯甲醛在体外试验中表现出杀线虫活性，浓度为 250 µg ml。预测在 48 小时暴露后杀死 50%和 95%第二代幼虫的 4-乙基苯甲醛有效剂量分别为 35 和 88 µg ml。在体外试验中，浓度为 150 µg ml 的 4-乙基苯甲醛可将卵孵化率降低到与商业杀线虫剂 fluensulfone（浓度为 200 µg ml）相似（>0.05）的值。在植物试验中，作为土壤熏蒸剂，剂量为 1 毫升/升基质的 4-乙基苯甲醛的效果与商业熏蒸剂 Dazomet（250 µg ml）相似（>0.05）。因此，4-乙基苯甲醛具有作为新型杀线虫剂开发的潜力。
