The relative importance of factors determining geneticdrift: mating system, spatial genetic structure, habitatand census size in Arabidopsis lyrata
Maattanen K and Yvonne W. 2010. The relative importance of factors determining geneticdrift: mating system, spatial genetic structure, habitatand census size in Arabidopsis lyrata. New Phytologist. 188
Summary• The mating system, dispersal and census size are predicted to determine themagnitude of genetic drift, but little is known about their relative importance innature.• We estimated the contributions of several population-level features to geneticdrift in 18 populations of Arabidopsis lyrata. The factors were outcrossing rate,within-population spatial genetic structure, census size and substrate type. Theexpected heterozygosity (HE) at 10 microsatellite loci was taken to reflect theeffective population size (Ne) and the strength of genetic drift.• The mating system explained most of the variation in HE (60%), followed bysubstrate (10%), genetic structure (9%) and census size (6%). The most outcrossingpopulation had a +0.32 higher predicted HE than the most selfing population; theestimated Ne of selfing populations was less than half that of outcrossing populations.Rocky outcrops supported populations with a +0.14 higher HE than didsandy substrates. The most structured population had a +0.24 higher HE than theleast structured population, and the largest population had a +0.18 higher HE thanthe smallest population.• This study illustrates the importance of outcrossing, genetic structure and the physicalenvironment – together with census size – in maintaining HE, and suggests thatmultiple population-level characteristics influenceNe and the action of genetic drift.
- Type
- Journal Article
- Authors
- Maattanen, Kirsti; Yvonne, Willi
- Units
- APIS , ISRO , PIRO
- Keywords
- Genetic Diversity, Inbreeding, outcrossing, plant mating system, selffertilization, small population size, small-scale spatial genetic structure