Physical state of epicuticular waxes during development of 'Tommy Atkins' mangoes.
Gazzola R., Alves R. E., Filgueiras H. A. C.
Author Affiliation: Embrapa Agroindústria Tropical, C.P. 3761, 60511-110, Fortaleza, CE, Brazil.
: 595-599
Abstract : Mango (cv. Tommy Atkins) fruits, 4-5 (Stage I), 7-8 (Stage II), 9-10 (Stage III) and 10-11 cm in length (Stage IV), were harvested in Mossoró, Rio Grande do Norte, Brazil. Peel samples were cut, placed on filter paper, dehydrated in a desiccator and examined under scanning electron microscope after being covered with gold. In Stage I, the waxes were seen as an amorphous layer with wax platelets in some areas completely covering the skin. Stomata at this stage were opened and functional. The guard cells were swollen and covered with waxes. In Stage II, the wax layer started to break and loosen. The physical structure of the waxes changed from amorphous to crystalline. Stomata were closed, covered with waxes and non-functional. Micro-fractures in the wax layer could be observed close to stomata. When the fruits reached Stage III, crystallization occurred. The micro-cracks seen in Stage II could still be observed. Stomata were completely closed and inactive. There were some sites without wax covering. In Stage IV, completely closed and clearly inactive stomata were seen. Waxes were almost completely crystalline and there were some parts without wax covering.