This study is part of the PhD thesis of A. Gilabert, which focused on the population genetics and the ecology of the aphid Rhopalosiphum padi. This work was supervised by C.-A. Dedryver, M. Plantegenest and J.-C. Simon, who are interested in aphid ecology and evolution. S. Stoeckel is a population geneticist interested in asexual reproduction and selection. L. Mieuzet is working on the genotypic and phenotypic characterization of aphids. F. Halkett worked on the ecological and genetic interactions between lineages of R. padi and now studies the ecology and the population genetics of the forest fungal pathogens.
Climate and agricultural context shape reproductive mode variation in an aphid crop pest
Article first published online: 15 JUN 2009
DOI: 10.1111/j.1365-294X.2009.04250.x
© 2009 Blackwell Publishing Ltd
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How to Cite
GILABERT, A., SIMON, J.-C., MIEUZET, L., HALKETT, F., STOECKEL, S., PLANTEGENEST, M. and DEDRYVER, C.-A. (2009), Climate and agricultural context shape reproductive mode variation in an aphid crop pest. Molecular Ecology, 18: 3050–3061. doi: 10.1111/j.1365-294X.2009.04250.x
Publication History
- Issue published online: 29 JUN 2009
- Article first published online: 15 JUN 2009
- Received 16 January 2009; revision received 15 April 2009; accepted 25 April 2009
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Keywords:
- Bayesian assignment;
- host alternating aphid;
- population structure;
- reproductive mode;
- Rhopalosiphum padi;
- sexual vs. asexual lineages
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.

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