Photosynthetic adaptation of Solanum dulcamara L. to sun and shade environments : I. A Comparison of Sun and Shade Populations.

The photosynthetic response properties of individuals of Solanum dulcamara L. collected from sun and shade habitats were compared in controlled environments. Light-saturated photosynthetic rates and seven additional parameters associated with photosynthetic and growth performance were measured over a range of 12 environmental conditions that simulated natural habitat differences in light intensity, moisture availability and daily temperature amplitude. In contrast to previous studies, the results suggest there is no ecotypic differentiation with respect to the sun and shade environments from which the individuals were collected. It appears that all but one of the field-collected individuals are capable of successfully inhabiting the full range of light environments from which the species was collected.