Molecular Ecology (2009) 18, 3050-3061

A. Gilabert, J.-C. Simon, L. Mieuzet, F. Halkett, S. Stoeckel, M. Plantegenest and C.-A. Dedryver (2009)
Climate and agricultural context shape reproductive mode variation in an aphid crop pest
Molecular Ecology 18 (14), 3050-3061
Abstract: In aphids, reproductive mode is generally assumed to be selected for by winter climate. Sexual lineages produce frost-resistant eggs, conferring an advantage in regions with cold winters, while asexual lineages predominate in regions with mild winters. However, habitat and resource heterogeneities are known to exert a strong influence on sex maintenance and might modulate the effect of climate on aphid reproductive strategies. We carried out a hierarchical sampling in northern France to investigate whether reproductive mode variation of the aphid Rhopalosiphum padi is driven by winter climate conditions, by habitat and resource heterogeneities represented by a range of host plants or by both factors. We confirmed the coexistence in R. padi populations of two genetic clusters associated with distinct reproductive strategies. Asexual lineages predominated, whatever the surveyed year and location. However, we detected a between-year variation in the local contribution of both clusters, presumably associated with preceding winter severity. No evidence for host-driven niche differentiation was found in the field on six Poaceae among sexual and asexual lineages. Two dominant multilocus genotypes (~70% of the sample), having persisted over a 10-year period, were equally abundant on different plant species and locations, indicating their large ecological tolerance. Our results fit theoretical predictions of the influence of winter climate on the balance between sexual and asexual lineages. They also highlight the importance of current agricultural practices which seem to favour a small number of asexual generalist genotypes and their migration across large areas of monotonous environments.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Charles-Antoine Dedryver

Research topic(s) for pests/diseases/weeds:
molecular biology - genes
environment - cropping system/rotation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Rhopalosiphum padi		France