Fang Ming, Long Wenxin, Sun Jie, Wang Ailing, Chen Lei, Cui Yonghe, Huang Zhihua, Li Jiangzhou, Ruan Weibin, Rasmann Sergio, Wei Xianqin
College of Life Sciences, Nankai University, Tianjin, China.
School of Mathematical Sciences and LPMC, Nankai University, Tianjin, China.
Pest Manag Sci. 2023 Dec;79(12):5162-5172. doi: 10.1002/ps.7719. Epub 2023 Sep 19.
Root-knot nematodes (RKNs), including Meloidogyne species, are among the most destructive plant-parasites worldwide. Recent evidence suggests that entomopathogenic fungi (EPF) can antagonize RKNs. Such antagonistic effects are likely mediated by toxic metabolites, including volatile organic compounds (VOCs), produced by the fungi. However, how widespread these effects are across EPF species, and which VOCs mediate negative interactions between EPF and RKNs needs to be further elucidated.
First, we evaluated the nematicidal effect of VOCs emitted by 46 EPF isolates against Meloidogyne incognita and found variable toxicity depending on the isolate. Second, we measured the nematicidal effect of highly toxic isolates, including species in the genus Talaromyces, Aspergillus, Clonostachys, and Purpureocillium and, third, we analyzed the nematicidal effect of major VOCs, including 2-methyl-1-propanol, 3-methyl-1-butanol, isopropyl alcohol and 2-methyl-3-pentanone. The mortality of M. incognita juveniles (J2s) was generally high (50%) either via airborne or in-solution contact with VOCs. Moreover, the tested VOCs significantly inhibited egg hatching, and repelled J2s away from the VOCs.
This study not only provides insights into the ecological function of VOCs in the rhizosphere, but also provides new approaches for developing environmentally friendly control methods of RKNs in agroecosystems. © 2023 Society of Chemical Industry.
根结线虫（RKNs），包括南方根结线虫属的物种，是全球最具破坏性的植物寄生虫之一。最近的证据表明，昆虫病原真菌（EPF）可以拮抗根结线虫。这种拮抗作用可能是由真菌产生的有毒代谢产物介导的，包括挥发性有机化合物（VOCs）。然而，这些效应在昆虫病原真菌物种中的普遍程度以及哪些挥发性有机化合物介导了昆虫病原真菌与根结线虫之间的负面相互作用，还有待进一步阐明。
首先，我们评估了46株昆虫病原真菌分离株释放的挥发性有机化合物对南方根结线虫的杀线虫作用，发现不同分离株的毒性存在差异。其次，我们测量了高毒性分离株的杀线虫作用，包括篮状菌属、曲霉属、枝顶孢属和拟青霉属的物种，第三，我们分析了主要挥发性有机化合物的杀线虫作用，包括2-甲基-1-丙醇、3-甲基-1-丁醇、异丙醇和2-甲基-3-戊酮。南方根结线虫幼虫（J2s）通过空气传播或与挥发性有机化合物溶液接触的死亡率通常很高（50%）。此外，测试的挥发性有机化合物显著抑制了卵的孵化，并使J2s远离挥发性有机化合物。
本研究不仅深入了解了挥发性有机化合物在根际的生态功能，还为开发农业生态系统中根结线虫的环境友好控制方法提供了新途径。© 2023化学工业协会。
