Intraspecific variability in the response to light quality in Crotalaria incana and Impatiens sultanii

Abstract

To study some aspects of intraspecific variability, half-sib families of Crotalaria incana L. and Impatiens sultanii Hook. f. were grown in the field exposed to reflected light of either high or low red to far-red ratio, without direct shading. Plants of both species responded to the light quality of the reflected light. Crotalaria plants were more responsive; a reduction in the red to far-red ratio in reflected light produced a significant increase in height, internode length, petiole length, leaf area, and dry weight. In Impatiens, only internode length was significantly increased by this treatment. For some traits, in both species, half-sib families differed significantly in the response to the light treatments. For several characters there were significant interactions between the light-quality treatment and family, suggesting that the response to light quality may have a genetic component. The changes induced by an alteration in light quality may have important fitness consequences.Key words: intraspecific variability, red to far-red ratio, morphological traits, Crotalaria incana, Impatiens sultanii.