Studying genetics of adaptive variation in model organisms: flowering time variation in Arabidopsis lyrata

Abstract

Arabidopsis thaliana has emerged as a model organism for plant developmental genetics, but it is also now being widely used for population genetic studies. Outcrossing relatives of A. thaliana are likely to provide suitable additional or alternative species for studies of evolutionary and population genetics. We have examined patterns of adaptive flowering time variation in the outcrossing, perennial A. lyrata. In addition, we examine the distribution of variation at marker genes in populations form North America and Europe. The probability of flowering in this species differs between southern and northern populations. Northern populations are much less likely to flower in short than in long days. A significant daylength by region interaction shows that the northern and southern populations respond differently to the daylength. The timing of flowering also differs between populations, and is made shorter by long days, and in some populations, by vernalization. North American and European populations show consistent genetic differentiation over microsatellite and isozyme loci and alcohol dehydrogenase sequences. Thus, the patterns of variation are quite different from those in A. thaliana, where flowering time differences show little relationship to latitude of origin and the genealogical trees of accessions vary depending on the genomic region studied. The genetic architecture of adaptation can be compared in these species with different life histories.

Genome-wide effects of postglacial colonization in Arabidopsis lyrata

“…As such, it is a more tractable organism for population genetics and allows addressing evolutionary questions and testing the validity of theoretical models (Riihimäki et al, 2005). For instance, A. lyrata, together with other species of the genus Arabidopsis, is intensively used for the study of self-incompatibility evolution (Mable et al, 2005;Schierup et al, 2006) or the genetic basis of adaptation at different geographic scales (for example, Kärkkäinen et al, 2004;Riihimäki et al, 2005, Kivimäki et al 2007.…”

Local adaptation and the evolution of species’ ranges under climate change

“…Considerable empirical evidence indicates that locally adapted phenotypes are 100 commonplace within many species (Lambrechts et al, 1996;McNeilly and Antonovic, 1968;Riihimaki et al, 2005;Santamaria et al, 2003). For example, it has long been known that many plant species show genetic differentiation in the timing of flowering McNeilly and Antonovic (1968); this variation is frequently clinal with 104 northern populations consistently different from southern counterparts (Riihimaki et al, 2005).…”

“…For example, it has long been known that many plant species show genetic differentiation in the timing of flowering McNeilly and Antonovic (1968); this variation is frequently clinal with 104 northern populations consistently different from southern counterparts (Riihimaki et al, 2005). Occurrence of a genotype outside of its usual range may result in 106 suboptimal flowering time and a corresponding reduction in fitness.…”

Complex Genetic Effects on Early Vegetative Development Shape Resource Allocation Differences BetweenArabidopsis lyrataPopulations

“…A. lyrata has a wide but highly fragmented distribution across Europe, Asia, and North America, and occurs in environments that range from subarctic and alpine to warm temperate in climate. A. lyrata also exhibits strong patterns of phenotypic variation between populations in flowering time (Riihimäki and Savolainen 2004;Riihimäki et al 2005) and fitness components (Kuittinen et al 2008;Leinonen et al 2009Leinonen et al , 2011. The complete genome sequence of A. lyrata has now been published (Hu et al 2011) and genetic and chromosomal synteny maps have been developed (Kuittinen et al 2004;Schranz et al 2006), greatly facilitating application of the extensive genomic resources and functional information available in A. thaliana to A. lyrata.…”