Table_4_Sustainable strategies for management of the “false root-knot nematode” Nacobbus spp.pdf

The genus Nacobbus, known as the false root-knot nematode, is native to the American continent and comprises polyphagous species adapted to a wide range of climatic conditions. Alone or in combination with other biotic and abiotic factors, Nacobbus spp. can cause significant economic yield losses on main food crops such as potato, sugar beet, tomato, pepper and bean, in South and North America. Although the genus distribution is restricted to the American continent, it has quarantine importance and is subject to international legislation to prevent its spread to other regions, such as the European Union. The management of Nacobbus spp. remains unsatisfactory due to the lack of information related to different aspects of its life cycle, survival stages in the soil and in plant material, a rapid and reliable diagnostic method for its detection and the insufficient source of resistant plant genotypes. Due to the high toxicity of chemical nematicides, the search for alternatives has been intensified. Therefore, this review reports findings on the application of environmentally benign treatments to manage Nacobbus spp. Biological control strategies, such as the use of different organisms (mainly bacteria, fungi and entomopathogenic nematodes) and other eco-compatible approaches (such as metabolites, essential oils, plant extracts, phytohormones and amendments), either alone or as part of a combined control strategy, are discussed. Knowledge of potential sources of resistance for genetic improvement for crops susceptible to Nacobbus spp. are also reported. The sustainable strategies outlined here offer immediate benefits, not only to counter the pathogen, but also as good alternatives to improve crop health and growth.

Nacobbus属，俗称伪根结线虫（false root-knot nematode），原生分布于美洲大陆，包含多食性物种，可适应广泛的气候条件。在南美与北美地区，该属线虫单独或与其他生物、非生物因素协同作用时，可对马铃薯、甜菜、番茄、辣椒、菜豆等主要食用与经济作物造成显著的经济产量损失。尽管该属线虫的分布范围仅局限于美洲大陆，但其具有检疫重要性，受到国际立法管控以防止其传播至欧盟等其他地区。目前针对Nacobbus属线虫的防治手段仍不尽如人意，原因在于其生命周期各环节、土壤及植物材料中的存活阶段等相关研究信息不足，缺乏快速可靠的检测诊断方法，且抗该线虫的植物基因型资源匮乏。鉴于化学杀线虫剂毒性较高，相关替代防治方案的研发工作正不断加强。有鉴于此，本综述总结了利用环境友好型防治手段管控Nacobbus属线虫的相关研究成果。本文探讨了各类生物防治策略，如利用不同微生物（主要为细菌、真菌及昆虫病原线虫）及其他生态兼容型防治方法（如代谢物、精油、植物提取物、植物激素及土壤改良剂），既可单独施用，也可作为综合防治策略的组成部分。此外，本文还梳理了针对易受Nacobbus属线虫侵染的作物进行遗传改良所需的潜在抗性资源相关研究进展。本文所概述的可持续防治策略，不仅可直接用于应对该病原物，同时也是改善作物健康状况与生长表现的优质替代方案。