CUTICULAR CHANGES DURING THE ONTOGENY OF Mangifera indica L. FRUITS

Abstract

Cuticle covers fruits surface and one of its functions is to restrict water loss as water vapor. This barrier is related to the physical and chemical properties of the cuticle. In this work we studied cuticle changes during the ontogeny of ‘Tommy Atkins’, ‘Kent’ and ‘Keitt’ mango (Mangifera indica L.) fruits. Fruits were randomly sampled from an orchard at Navojoa, Sonora, México. This study was done at two stages: during fruit growth and storage. A completely randomized design with three replications was used. The content of waxes (epicuticular and intracuticular) and cutin, cuticle weight and thickness, surface ultrastructure and permeability of cuticles along fruit ontogeny were measured in each sample. Results showed differences among cultivars regarding the variables analyzed. Epicuticular wax content increased during fruit growth, while during storage it presented changes along the evaluation. Cutin represented between 60 and 80 % of cuticle weight, while the rest corresponded to waxes. Waxes ultrastructure showed varietal differences at harvest: ‘Tommy Atkins’ and ‘Kent’ presented major proportion of crystalline zones (82.6 %), whereas in ‘Keitt’ it was mostly amorphous (74.1 %). The best efficiency of cuticles in regulating water losses was at harvest and it was related to wax ultrastructure and WAX content.