Differences in Leaf Cuticle Structure and Efficacy among Eastern Redbud and Mexican Redbud Phenotypes

Abstract

The objective of this study was to compare the structure and efficacy in terms of retarding cuticular transpiration of leaf cuticles from eastern redbud (Cercis canadensis L.) and dull-leaf and glossy-leaf Mexican redbud [Cercis canadensis var. mexicana (Rose) M. Hopk.]. Leaves of Mexican redbud exhibited several xeromorphic characteristics compared to eastern redbud: a smaller, thicker leaf with thicker cuticles, more cuticular wax, a higher specific leaf mass, and greater hydrated water content on a leaf area basis. Mexican redbuds with a glossy leaf differed from those with a dull leaf only in a thicker adaxial cuticle lacking wax crystallite on the surface. Epicuticular wax crystallite were present on the abaxial surface of all leaves examined. Detached leaves of eastern redbud had a higher water loss rate than those of Mexican redbud only on a dry mass basis, not on a leaf area basis. There was no difference in the rate of water loss by detached leaves of glossy-leaf and dull-leaf Mexican redbuds after 4 hours.