Quantitative Cellular Evaluation and Anatomical Organization of the External Region of Different Genetic Materials and Maturation Stages of Tomato Processing

Abstract

The effect of the anatomical structure of tomato skin may be significant for quality determination at the harvest point, but the definitions of cells that constitute the skin of fleshy fruits, such as tomato, are still unclear, providing contradictory descriptions. The aim of this study was to evaluate the epidermal tissue of different genetic materials of tomato processing (IT761, U2006, TC2736, CVR2909 and F3060) and maturation stage, in order to compare and choose genetic materials with morphological characteristics of the epidermis region more appropriate for the bulk transport. Micrographs were used for cell measurements using the Image J software. Cuticle undergoes thickening during fruit growth, and reduction in full maturation. Genetic materials presenting fruits with thicker cuticle at the harvest stage (CVR2909, F3060 and IT761) were more advantageous due to their mechanical resistance. Cuticle deposition ends before full fruit maturation, resulting in a decrease in the amount of cutin per surface unit, consequently decreasing cuticle thickness in the ripe fruit. The characteristics observed in the tomato fruit mesocarp clearly showed the disruption of the cell wall during the fourth maturation stage related to loss of fruit firmness. Among the new genetic materials, F3060 has a greater potential to become cultivated for industrialization due to its morphological characteristics, such as elevated cuticle thickness and high values for width, height, perimeter and area of epidermal cells in full maturation stage, which make it suitable for bulk transport.

Maturation and determination of the harvest point of Capsicum chinense Jacq. (‘biquinho’ pepper)

“…It is possible to confirm this with the correlation of split fruits with fruit weight and size and the inverse relationship with the color parameters (Figures 2 and 3), showing that as the fruits advance in maturity, there is a tendency of rupture occurrences. Such factor may also be associated with cuticle thickness, as according to Vieira et al (2020) when analyzing tomatoes at different stages of maturation, found that cuticle thickening increases during development and decreases in fully ripe fruits. This is due to the fact that cuticle deposition ceases before complete ripening of the fruits, so that ripe fruits have less cuticle per surface unit, meaning, thinner cuticle.…”

“…The loss of water, either by the decrease of turgidity due to cracks or by the increase of respiratory activity, is one of the main problems of postharvest, resulting in the loss of luminosity, weight and shrinkage of the fruits (Figure 3), causing the useful life of pepper fruits to be reduced (Aloni et al, 1999;Finger & Pereira, 2016). Therefore, the thicker the cuticle is at the harvest stage, the longer will be the durability of this fruit (Vieira et al, 2020). Thus, it is important that the fruit harvest is performed at the optimal maturity stage to minimize water losses during storage and the marketing period (Lufu et al, 2020).…”