title: Genetic changes in flowering and morphology in response to adaptation to a high-latitude environment in Arabidopsis lyrata.
abstract: OBJECTIVE
  The adaptive plastic reactions of plant populations to changing climatic factors, such as winter temperatures and photoperiod, have changed during range shifts after the last glaciation. Timing of flowering is an adaptive trait regulated by environmental cues. Its genetics has been intensively studied in annual plants, but in perennials it is currently not well characterized. This study examined the genetic basis of differentiation in flowering time, morphology, and their plastic responses to vernalization in two locally adapted populations of the perennial Arabidopsis lyrata: (1) to determine whether the two populations differ in their vernalization responses for flowering phenology and morphology; and (2) to determine the genomic areas governing differentiation and vernalization responses.
  
  
  METHODS
  Two A. lyrata populations, from central Europe and Scandinavia, were grown in growth-chamber conditions with and without cold treatment. A QTL analysis was performed to find genomic regions that interact with vernalization.
  
  
  RESULTS
  The population from central Europe flowered more rapidly and invested more in inflorescence growth than the population from alpine Scandinavia, especially after vernalization. The alpine population had consistently a low number of inflorescences and few flowers, suggesting strong constraints due to a short growing season, but instead had longer leaves and higher leaf rosettes. QTL mapping in the F2 population revealed genomic regions governing differentiation in flowering time and morphology and, in some cases, the allelic effects from the two populations on a trait were influenced by vernalization (QTL × vernalization interactions).
  
  
  CONCLUSIONS
  The results indicate that many potentially adaptive genetic changes have occurred during colonization; the two populations have diverged in their plastic responses to vernalization in traits closely connected to fitness through changes in many genomic areas.
authors.affiliation: Department of Biology, University of Oulu, PO Box 3000, FIN-90401 Oulu, Finland. benedicte.quilot@avignon.inra.fr
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Quilot-Turion
authors.forename: Johanna
authors.initials: J
authors.lastname: Leppälä
authors.forename: Päivi H
authors.initials: PH
authors.lastname: Leinonen
authors.forename: Patrik
authors.initials: P
authors.lastname: Waldmann
authors.forename: Outi
authors.initials: O
authors.lastname: Savolainen
authors.forename: Helmi
authors.initials: H
authors.lastname: Kuittinen
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000531:Altitude; D017360:Arabidopsis / Q000033:anatomy & histology* / Q000235:genetics*; D003080:Cold Temperature; D003433:Crosses, Genetic; D004777:Environment; D035264:Flowers / Q000033:anatomy & histology* / Q000235:genetics* / Q000502:physiology; D008040:Genetic Linkage; D005858:Germany; D006720:Homozygote; D009664:Norway; D040641:Quantitative Trait Loci / Q000235:genetics