Temporal 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.

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.

Temporal sampling helps unravel the genetic structure of naturally occurring populations of a phytoparasitic nematode. 1. Insights from the estimation of effective population sizes.

The sustainability of modern agriculture relies on strategies that can control the ability of pathogens to overcome chemicals or genetic resistances through natural selection. This evolutionary potential, which depends partly on effective population size (N e ), is greatly influenced by human activities. In this context, wild pathogen populations can provide valuable information for assessing the long-term risk associated with crop pests.

Heterozygote deficits in cyst plant-parasitic nematodes: possible causes and consequences.

Deviations of genotypic frequencies from Hardy-Weinberg equilibrium (HWE) expectations could reveal important aspects of the biology of populations. Deviations from HWE due to heterozygote deficits have been recorded for three plant-parasitic nematode species. However, it has never been determined whether the observed deficits were due (i) to the presence of null alleles, (ii) to a high level of consanguinity and/or (iii) to a Wahlund effect.

Movement propensity and ability correlate with ecological specialization in European land snails: comparative analysis of a dispersal syndrome.

Intra- and interspecific differences in movement behaviour play an important role in the ecology and evolution of animals, particularly in fragmented landscapes. As a consequence of rarer and generally more fragmented habitat, and because dispersal tends to disrupt benefits brought by local adaptation, theory predicts that mobility and dispersal should be counter-selected in specialists. Using experimental data and phylogenetic comparative tools, we analysed movement propensity and capacity, as well as dispersal-related phenotypic traits, in controlled conditions in 20 species of European land snails from the Helicoidea superfamily.

Comparison between one midline cutaneous incision and two lateral incisions in the lumbar paraspinal approach by Wiltse: a cadaver study.

Wiltse has described in 1968 an intermuscular lumbar approach with two vertical incisions made at 30 mm each on both sides of the midline. Since 1988, Wiltse recommends to practice a single median incision because of aesthetic arguments and because it avoids potential difficulties in case of iterative surgery. In this paper, the goal of authors was to determine the advantages of two lateral incisions, particularly in term of cutaneous vascularization.