Foliar variegation is often assumed to be due to lack of chlorophyll or the presence of special pigments in sections of a leaf, but it can also result from leaf structural variation. Sheue et al. show that naturally occurring foliar variegation in six species and one cultivar of Begonia is due to air spaces above the chlorenchyma, situated either below the adaxial epidermis or below the adaxial water-storage tissue. Photosynthetic functioning is retained in the light areas of the leaves, and these areas do not include primary veins, potentially limiting the costs of variegation.
One Response to “Photosynthetic costs of foliar variegation in Begonia”
Ken Thompson has written an informative piece about variegation in garden plants in The Daily Telegraph, September 2012: http://www.telegraph.co.uk/gardening/9526612/Variegation-is-the-spice-of-life.html which cites Sheue et al. The original paper is now freely accessible at http://dx.doi.org/10.1093/aob/mcs025 or http://aob.oxfordjournals.org/content/109/6/1065