The plant-parasitic nematode Nacobbus aberrans s.l. is a major agricultural pest of quarantine importance worldwide and is one of the top 10 nematodes in plant pathology because it causes significant losses in several crops. There are evidences of the existence of a species complex, with species being difficult to discriminate using only morphological characters. In this study, we aimed at resolving the taxonomic situation from a multi-disciplinary approach, based on morphometric data and molecular analyses. The results supported the identification of three nominal species in the complex: N. aberrans s.s., N. bolivianus and a new taxon, Nacobbus celatus sp. n. This new species, described based on the revision of published and new data, is widely distributed in the lowlands of Argentina. Our results also evidence the possible existence of a new taxon native to the Andean region of the same country. For the first time, the utility of cytochrome oxidase c subunit 1 barcoding for Nacobbus species identification is corroborated. This study also includes the estimation of divergence time among Nacobbus spp.; the possible geographical origin of the genus and colonization pattern are discussed. The present work shows the usefulness of an integrated approach to the resolution of systematic problems.

中文翻译：

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使用综合分类法解密 Nacobbus aberrans (Nematoda: Pratylenchidae) 复合体中的物种

植物寄生线虫Nacobbus aberrans S.L。线虫是世界范围内具有检疫重要性的主要农业害虫，并且是植物病理学中排名前 10 的线虫之一，因为它会导致多种作物的重大损失。有证据表明存在物种复合体，仅使用形态特征难以区分物种。在这项研究中，我们旨在基于形态测量数据和分子分析，从多学科方法解决分类学情况。结果支持识别复合物中的三个标称物种：N。 aberrans s.s. , N. bolivianus和一个新的分类群Nacobbus celatussp. n. 这一新物种根据已发表和新数据的修订进行描述，广泛分布在阿根廷的低地。我们的结果还证明了同一国家安第斯地区可能存在一种新的分类群。首次证实了细胞色素氧化酶c亚基 1 条形码用于Nacobbus物种鉴定的效用。该研究还包括对Nacobbus spp.之间发散时间的估计；讨论了该属的可能地理起源和殖民模式。目前的工作显示了解决系统问题的综合方法的有用性。