The cuticles of citrus species. Composition of the intracuticular lipids of leaves and fruits

Abstract

The qualitative and quantitative compositions of the intracuticular lipids of the leaves and fruits of four species of Citrus have been examined. The leaf cuticular membranes (280–316 μg/cm²) were well developed and contained high proportions of cutin (77–87%) of which isomers of dihydroxyhexadecanoic acid (79–82%) were the most abundant monomers. The fruit membranes (221–271 μg/cm²) contained smaller proportions of cutin (59–67%) whose major monomeric constituents were dihydroxyhexadecanoic acid (30–62%) and 16‐hydroxyoxo‐hexadecanoic acid (21–57%). The substantial amounts of cuticular wax (34–68 μg/cm²) located within the membranes consisted largely of fatty acids (68–97%) with hexadecanoic acid (44–78%) and octadecanoic acid (11–39%) present as the main components.