Differences in distribution and community structure of plant-parasitic nematodes in pecan orchards between two ecoregions of Georgia

Ganpati B Jagdale; Timothy B Brenneman; Paul M Severns; David Shapiro-Ilan

doi:10.21307/jofnem-2021-075

Differences in distribution and community structure of plant-parasitic nematodes in pecan orchards between two ecoregions of Georgia

J Nematol. 2021 Sep 7:53:e2021-75. doi: 10.21307/jofnem-2021-075. eCollection 2021.

Authors

Ganpati B Jagdale¹, Timothy B Brenneman², Paul M Severns³, David Shapiro-Ilan⁴

Affiliations

¹ Extension Nematology Lab, Department of Plant Pathology, University of Georgia, 2350 College Station Road, Athens, GA, 30602.
² Department of Plant Pathology, University of Georgia, 2360 Rainwater Rd., Tifton, GA, 31793-5766.
³ Department of Plant Pathology, University of Georgia, 120 Carlton St, Athens, GA, 30602.
⁴ USDA, Agricultural Research Service, SE Fruit and Tree Nut Research Laboratory, 21 Dunbar Rd, Byron, GA, 31008.

Abstract

In Georgia, pecans are commercially grown in the Piedmont and Coastal Plain ecoregions which are characterized by sandy-loam, sandy, and/or clay soils. If well-drained, these soils are suitable for pecan production, but the soil characteristics differ enough between ecoregions in which the plant-parasitic nematode (PPN) communities could differ substantially. We studied PPN communities in pecan orchards to evaluate the potential for ecoregion differences. In total, 11 genera (Helicotylenchus, Hemicycliophora, Heterodera, Hoplolaimus, Meloidogyne, Mesocriconema, Pratylenchus, Paratylenchus, Paratrichodorus, Tylenchorhynchs, Xiphenema) were recovered from pecan orchards in the Piedmont and Coastal Plain ecoregions. However, Non-Metric Multi-Dimensional Scaling ordination, Multi-Rank Permutation Procedure, and Indicator Species Analyses indicated that the pecan PPN communities strongly differed between ecoregions and that different genera were strongly associated with different ecoregions. For 9 of the 11 PPN genera, the maximum counts occurred in Coastal Plain locations, suggesting that the well-drained sandy soils of the Coastal Plain and comparatively ill-drained red clay soils of the Piedmont may be conducive and unfavorable for movement/reproduction of PPNs, respectively.

Keywords: Ecology; Host-parasite relationship; Multivariate analyses; Non-metric multi-dimensional analyses.