High genetic diversity and geographic subdivision of three lance nematode species (Hoplolaimus spp.) in the United States Claudia M. Holguin1, Juan A. Baeza2, John D. Mueller3 & Paula Agudelo1 1Department of Agricultural and Environmental Sciences, Clemson University, Clemson, South Carolina 29634 2Department of Biological Sciences, Clemson University, Clemson, South Carolina 29634 3Edisto Research and Education Center, Clemson University, Blackville, South Carolina 29817 Keywords Abstract Barcoding, genetic variability, Hoplolaimus spp., lance nematodes, phylogeny. Lance nematodes (Hoplolaimus spp.) feed on the roots of a wide range of plants, some of which are agronomic crops. Morphometric values of amphimic- Correspondence tic lance nematode species overlap considerably, and useful morphological char- Paula Agudelo, Department of Agricultural acters for their discrimination require high magnification and significant and Environmental Sciences, Clemson diagnostic time. Given their morphological similarity, these Hoplolaimus species University, Clemson, SC 29634. provide an interesting model to investigate hidden diversity in crop agroecosys- Tel: 864 656-5741 tems. In this scenario, H. galeatus may have been over-reported and the related Fax:864-656-4960 E-mail:
[email protected] species that are morphologically similar could be more widespread in the Uni- ted States that has been recognized thus far. The main objectives of this study Funding Information were to delimit Hoplolaimus galeatus and morphologically similar species using Research was supported by Cotton morphology, phylogeny, and a barcoding approach, and to estimate the genetic Incorporated, Project No. 14-506SC and the diversity and population structure of the species found. Molecular analyses were United States Department of Agriculture performed using sequences of the cytochrome c oxidase subunit 1 (Cox1) and USDA-NIFA, Contract Number: 2010-51101- the internal transcribed spacer (ITS1) on 23 populations.