Floral traits determine the reproductive success and the fitness of a plant.We investigated the effect of ambient temperature on three floral and four fitness traits and their plasticities in 34 Arabidopsis thaliana accessions grown at 17 C, 20 C, 24 C, and 27 C.Based on reaction norms of the mean trait values across temperatures, we found that these traits exhibited different degrees of temperature-mediated plasticity.Flower number, measured as number of siliques, and number of seeds per silique, showed significant positive correlation with total seed number at each tested temperature, indicating that seed number in siliques is an indicator for reproductive output.The correlation of flower size with the latitudinal origin of the accessions indicates that in the north, larger flowers may confer an adaptive advantage.Altogether, this study provides information on the impact of increased temperature on fitness in selfing A. thaliana.
Hoffmann et al. (Mon,) studied this question.