Comparison of morphological and physiological characteristics in two phenotypes of a rare and endangered plant, Begonia fimbristipula Hance

The rare and endangered plant, Begonia fimbristipula, shows red and green phenotypes, differentiated by a coloration of the abaxial leaf surface. In this study, we compared morphological and physiological traits of both phenotypes. The results showed that the red phenotype contained a significantly higher chlorophyll content, closer arrangement of chloroplasts, and a more developed grana. In addition, the red phenotype transferred significantly more light energy into the electron transport during the photoreaction. Similarly, the maximum photosynthetic rate, instantaneous water-use and light-use efficiencies of the red B. fimbristipula were all significantly higher than those of the green individuals. The differentiation between these two phenotypes could be caused by their different survival strategies under the same conditions; epigenetic variations may be in some correlation with this kind of phenotype plasticity. Red B. fimbristipula has an advantage in resource acquisition and utilization and possesses a better self-protection mechanism against changes in environmental conditions, therefore, it might adapt better to global climate change compared to the green phenotype. Further studies on the possible epigenetic regulation of those phenotypic differentiations are needed.