XVI International Botanical Congess

We have conducted an experiment to examine potentially adaptive responses of Arabidopsis thaliana to two levels of light intensity, examining 45 lines of wide geographic origin. Six traits showed genetic variation for plasticity to light intensity. One of these traits represents a novel phenotype: plants under low light developed larger bracts than under high light. Several other plastic traits also behaved according to functional adaptive hypotheses. We performed Common Principal Component Analyses to compare genetic covariance matrices of the same families from both light treatments to investigate plasticity of multivariate genetic parameters. Results show that the matrices differ between treatments, implying that the G-matrix is environmentally labile. This in turn means that selection on the multivariate phenotype would have different outcomes depending on the environment.Anna Maleszyk