Open AccessTemporal sampling helps unravel the genetic structure of naturally occurring populations of a phytoparasitic nematode. 2. Separating the relative effects of gene flow and genetic drift
Author(s) -
Gracianne Cécile,
Jan PierreLoup,
Fournet Sylvain,
Olivier Eric,
Arnaud JeanFrançois,
Porte Catherine,
BardouValette Sylvie,
Denis MarieChristine,
Petit Eric J.
Publication year - 2016
Publication title -
evolutionary applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.776
H-Index - 68
ISSN - 1752-4571
DOI - 10.1111/eva.12401
Subject(s) - biology , biological dispersal , heterodera schachtii , gene flow , genetic structure , genetic drift , ecology , local adaptation , genetic diversity , genetic variation , pest analysis , population , isolation by distance , evolutionary biology , nematode , botany , genetics , gene , demography , sociology
Studying wild pathogen populations in natural ecosystems offers the opportunity to better understand the evolutionary dynamics of biotic diseases in crops and to enhance pest control strategies. We used simulations and genetic markers to investigate the spatial and temporal population genetic structure of wild populations of the beet cyst nematode Heterodera schachtii on a wild host plant species, the sea beet ( Beta vulgaris spp. maritima ), the wild ancestor of cultivated beets. Our analysis of the variation of eight microsatellite loci across four study sites showed that (i) wild H. schachtii populations displayed fine‐scaled genetic structure with no evidence of substantial levels of gene flow beyond the scale of the host plant, and comparisons with simulations indicated that (ii) genetic drift substantially affected the residual signals of isolation‐by‐distance processes, leading to departures from migration–drift equilibrium. In contrast to what can be suspected for (crop) field populations, this showed that wild cyst nematodes have very low dispersal capabilities and are strongly disconnected from each other. Our results provide some key elements for designing pest control strategies, such as decreasing passive dispersal events to limit the spread of virulence among field nematode populations.