Phenological and morphological responses to different temperature treatments differ among a world-wide sample of accessions of Arabidopsis thaliana

A world-wide sample of 74 accessions of Arabidopsis thaliana was grown at two temperatures (14 and 22 °C). The main question raised in this study is whether the climate at the places of origin of the accessions correlates with their performances under experimental conditions. Sixteen morphological and five phenological characters were scored. The phenological responses to the temperatures correlate significantly with temperature data from the sites of origin of the accessions (monthly mean temperature of January, April and October). Accessions from cold areas develop faster in the warmer treatment. Accessions from warm areas are less retarded in their development in colder conditions. The results suggest that the observed patterns may have developed through climatic selection during the postglacial range expansion of Arabidopsis.