Filling gaps in our knowledge on the cuticle of mangoes (Mangifera indica) by analyzing six fruit cultivars: Architecture/structure, postharvest physiology and possible resistance to fruit fly (Tephritidae) attack

The cuticle is a critical barrier covering the surface of plant aerial organs. It is associated with important physiological and biological fruit traits, but few studies on this structure have been conducted in tropical fruit such as mango. Here, we have reported on a detailed investigation on the cuticle of six cultivars of mangoes (Kent, Tommy Atkins, Manila, Ataulfo, Criollo and Manililla), by combining several advanced microscopy tools and chemical analyses. All mango cultivars exhibited high variability in cuticle architecture, epicuticular wax layer (EWL) deposition, and different pattern of changes in cutin monomers. Mango cultivars exhibited different water transpiration rates, firmness and fruit quality appearance during postharvest shelf life (PSL), which could not be simply explained by an isolated cuticle structural feature. However, mango cuticles of premium mangos such as Kent, Tommy and Ataulfo displayed prominent cuticle deposition during PSL compared to other cultivars. Tommy fruit with large wax deposition, marginal number of lenticels and prominent cuticle thickening during PSL, exhibited lower percentage of weight lost by transpiration and less visual deterioration of all mango cultivars studied. In contrast, Criollo fruit, with a significant number of lenticels, small EWL, and marginal cuticle thickening during PSL were associated with the highest rate of water transpiration, fruit deterioration, and abscisic acid content. Our results partially explain the resistance patterns to fruit fly attack documented in earlier studies, clearly showing that cultivars such as Criollo are highly susceptible whereas Tommy, Kent, and Ataulfo are resistant because of the cuticle characteristics described in this study.