Integrative descriptions and molecular phylogeny of two new needle nematodes of the genus Longidorus (Nematoda: Longidoridae) from Spain

Needle nematodes have an economic importance by causing damage to a wide range of natural and cultivated plants not only by directly feeding on root cells, but also by transmitting plant nepoviruses. Two new Longidorus nematodes, Longidorus oakcrassus n. sp. and Longidorus oakgracilis n. sp., are described and illustrated from populations associated with the rhizosphere of Pyrenean oak (Quercus pyrenaica Wild.) in southern Spain. The taxonomic position of both new species within the genus was assigned using an integrative approach. Morphologically, L. oakcrassus n. sp. is characterized by a female with a large and robust body size (9.2–12.2 mm), lip region anteriorly flattened to slightly rounded and almost continuous or slightly offset by a depression with body contour, ca 25.5–32.0 μm wide, amphidial fovea with slightly asymmetrical lobes, stylet composed by an odontostyle moderately long (110.0–133.5 μm) and odontophore weakly developed, pharynx short ending in a terminal pharyngeal bulb with common arrangement of pharyngeal glands, tail short almost hemispherical shape. Longidorus oakgracilis n. sp. is characterized by having a moderately long and thin female body (5.4–7.9 mm in length), a bluntly-rounded lip region, set off from body contour by a slight depression, amphidial fovea funnel-shaped without lobe, odontostyle moderately long (94.0–106.0 μm), pharyngeal bulb with common arrangement of pharyngeal glands, short tail, bluntly hemispherical. The presence of males is common in both species. Integrative diagnosis was based on molecular data using D2-D3 expansion domains of the 28S rRNA, 18S rRNA, ITS1 rRNA and partial coxI gene sequences and morphology. Although different gene markers show variations in the phylogenetic relationships, phylogeny indicated that L. oakcrassus n. sp. is phylogenetically related with several species described from the Iberian Peninsula, including L. oakgracilis n. sp., which is clustered with L.cf. olegi, L. lusitanicus and L. silvestris.

Bibliographic Details

Main Authors:	Cai, Ruihang, Archidona-Yuste, Antonio, Cantalapiedra-Navarrete, C., Palomares Rius, Juan E., Castillo, Pablo
Other Authors:	Consejo Superior de Investigaciones Científicas (España)
Format:	artículo biblioteca
Published:	Springer Nature 2020-01
Subjects:	18S rDNA, 28S rDNA D2-D3, Species description, CoxI, ITS1, Longidorids, Phylogeny, Taxonomy,
Online Access:	http://hdl.handle.net/10261/226932 http://dx.doi.org/10.13039/501100011033 http://dx.doi.org/10.13039/100005156 http://dx.doi.org/10.13039/501100004543 http://dx.doi.org/10.13039/501100003339
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