High genetic diversity and geographic subdivision of three lance nematode species (Hoplolaimus spp.) in the United States. Issue 14 (3rd July 2015)

• Record Type: Journal Article
• Authors: Holguin, Claudia M.; Baeza, Juan A.; Mueller, John D.; Agudelo, Paula
• Is Part Of: Ecology and evolution. Volume 5:Issue 14(2015:Aug.)
• Page Start: 2929
• Page End: 2944
• Publication Date: 2015-07-03
• Subjects: Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.1568
• Languages: English
• ISSNs: 2045-7758

Abstract

<abstract abstract-type="main" id="ece31568-abs-0001"> <title>Abstract</title> <p>Lance nematodes (<italic>Hoplolaimus</italic> spp.) feed on the roots of a wide range of plants, some of which are agronomic crops. Morphometric values of amphimictic lance nematode species overlap considerably, and useful morphological characters for their discrimination require high magnification and significant diagnostic time. Given their morphological similarity, these <italic>Hoplolaimus</italic> species provide an interesting model to investigate hidden diversity in crop agroecosystems. In this scenario, <italic>H. galeatus</italic> may have been over‐reported and the related species that are morphologically similar could be more widespread in the United States that has been recognized thus far. The main objectives of this study were to delimit <italic>Hoplolaimus galeatus</italic> and morphologically similar species using morphology, phylogeny, and a barcoding approach, and to estimate the genetic diversity and population structure of the species found. Molecular analyses were performed using sequences of the cytochrome c oxidase subunit 1 (<italic>Cox</italic>1) and the internal transcribed spacer (ITS1) on 23 populations. Four morphospecies were identified: <italic>H. galeatus, H. magnistylus, H. concaudajuvencus, </italic> and <italic>H. stephanus, </italic> along with a currently undescribed species. Pronounced genetic structure correlated with geographic origin was found for all species, except for <italic>H. galeatus</italic>. <italic>Hoplolaimus galeatus</italic> also exhibited low genetic diversity and the shortest genetic distances among populations. In contrast, <italic>H. stephanus</italic>, the species with the fewest reports from agricultural soils, was the most common and diverse species found. Results of this project may lead to better delimitation of lance nematode species in the United States by contributing to the understanding the diversity within this group.</p> </abstract>