Migration load in plants: role of pollen and seed dispersal in heterogeneous landscapes

• Published in: Journal of evolutionary biology Vol. 21; no. 1; pp. 294 - 309
• Main Authors: LOPEZ, S, ROUSSET, F, SHAW, F.H, SHAW, R.G, RONCE, O
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 2008; Blackwell Publishing Ltd; Oxford University Press; Wiley
• Subjects: Adaptation; Biodiversity and Ecology; Biological Evolution; Botany; Dispersal; domain_sde.be.evo; Environmental Sciences; evolution; Evolutionary biology; Gene Flow; Genetic Drift; Genetic Load; Genetic Variation; Genetics; landscapes; Load distribution; local adaptation; metapopulation; Models, Genetic; plant adaptation; Plant populations; Plant reproduction; Pollen; Pollen - genetics; pollen flow; prediction; quantitative genetics; Quantitative Trait, Heritable; seed; Seed dispersal; Seeds; Seeds - genetics; Selection, Genetic; Thlaspi; Thlaspi - genetics; variance; dispersal • local adaptation • metapopulation • pollen • quantitative genetics • seed
• ISSN: 1010-061X; 1420-9101; 1420-9101
• DOI: 10.1111/j.1420-9101.2007.01442.x

Evolution of local adaptation depends critically on the level of gene flow, which, in plants, can be due to either pollen or seed dispersal. Using analytical predictions and individual-centred simulations, we investigate the specific influence of seed and pollen dispersal on local adaptation in plant populations growing in patchy heterogeneous landscapes. We study the evolution of a polygenic trait subject to stabilizing selection within populations, but divergent selection between populations. Deviations from linkage equilibrium and Hardy-Weinberg equilibrium make different contributions to genotypic variance depending on the dispersal mode. Local genotypic variance, differentiation between populations and genetic load vary with the rate of gene flow but are similar for seed and pollen dispersal, unless the landscape is very heterogeneous. In this case, genetic load is higher in the case of pollen dispersal, which appears to be due to differences in the distribution of genotypic values before selection.