González-Trujillo M M, Artal J, Vicente-Díez I, Blanco-Pérez R, Talavera M, Dueñas-Hernani J, Álvarez-Ortega S, Campos-Herrera R
Departamento de Viticultura. Instituto de las Ciencias de la Vid y del Vino (ICVV: Universidad de La Rioja, CSIC, Gobierno de La Rioja), 26007, Logroño, La Rioja, Spain.
ARTAL Smart Agriculture, Pol. Ind. Fuente del Jarro, 46988, Paterna, Valencia, Spain.
J Invertebr Pathol. 2024 Nov;207:108213. doi: 10.1016/j.jip.2024.108213. Epub 2024 Sep 28.
Entomopathogenic Xenorhabdus spp. bacteria, symbiont of the nematode Steinernema spp., shows potential for mitigating agricultural pests and diseases through bioactive compound production. The plant-parasitic nematode (PPN) Meloidogyne incognita affects the yield and quality of numerous crops, causing significant economic losses. We speculate that Cell-Free Supernatants (CFS) from Xenorhabdus spp. could reduce the impact of the root-knot nematode (RKN) M. incognita without negatively affecting entomopathogenic nematodes (EPNs), which are considered beneficial organisms. This study explored the activity of seven CFS against M. incognita (two populations, AL05 and Chipiona) and their possible effects on EPNs. The in vitro impact of CFS at 10 %, 40 %, and 90 % concentrations on nematode motility at four and 24 h were tested on the PPN M. incognita and two EPNs, S. feltiae and H. bacteriophora. Additionally, EPN viability and virulence were evaluated at two and five days. On the other hand, tomato plant-mesocosm experiments examined the activity of four CFS on M. incognita reproductive capacity and EPN virulence. In vitro exposure of M. incognita to 90 % concentration of CFS resulted in reductions of activity over 60 % after four hours of expossure in four out of seven CFS. In the in vitro evaluation of two species of EPNs, none of the CFS affected the activity across any tested doses after four hours of exposure nor after 24 h. Plant-mesocosm experiments showed that CFS application significantly reduced RKN galls, egg masses, and galling index. However, the virulence of both EPN species decreased 15 days after application, with a significant impact on S. feltiae. Overall, these findings suggest that CFS could be used as a bio-tool against M. incognita in tomato crops, mitigating its impact on plant growth. However, this study also highlights the necessity of investigating the effects of CFS on non-target organisms.
昆虫病原发光杆菌属细菌是斯氏线虫属线虫的共生菌，通过产生生物活性化合物显示出减轻农业病虫害的潜力。植物寄生线虫南方根结线虫会影响多种作物的产量和品质，造成重大经济损失。我们推测，发光杆菌属细菌的无细胞上清液（CFS）可以降低根结线虫对作物的影响，同时不会对被视为有益生物的昆虫病原线虫产生负面影响。本研究探讨了七种CFS对南方根结线虫（两个种群，AL05和奇皮奥纳）的活性及其对昆虫病原线虫可能产生的影响。在体外，分别以10%、40%和90%的浓度测试了CFS在4小时和24小时时对植物寄生线虫南方根结线虫以及两种昆虫病原线虫——斯氏线虫和嗜菌异小杆线虫运动能力的影响。此外，还在两天和五天时评估了昆虫病原线虫的活力和毒力。另一方面，番茄植株微宇宙实验研究了四种CFS对南方根结线虫繁殖能力和昆虫病原线虫毒力的影响。在体外将南方根结线虫暴露于90%浓度的CFS中，7种CFS中有4种在暴露4小时后活性降低了60%以上。在对两种昆虫病原线虫的体外评估中，暴露4小时和24小时后，所有测试剂量的CFS均未影响其活性。番茄植株微宇宙实验表明，施用CFS可显著减少根结线虫的虫瘿、卵块和虫瘿指数。然而，施用15天后，两种昆虫病原线虫的毒力均下降，对斯氏线虫的影响尤为显著。总体而言，这些发现表明，CFS可作为防治番茄作物南方根结线虫的生物工具，减轻其对植物生长的影响。然而，本研究也强调了研究CFS对非靶标生物影响的必要性。
