POST-HARVEST QUALITY OF 40 COLLECTIONS OF TOMATO (Solanum lycopersicum L.) NATIVE OF MEXICO

Abstract

In improving physical, chemical and nutritional quality of tomato fruit (Solanum lycopersicum L.), breeders often turn to wild stock to use its genetic variation. However, this generates the need to identify its qualities. The objective of this study was to characterize postharvest quality of the fruit of 40 native populations of Mexico through the study of physical, chemical and sensorial quality parameters to generate information to orient their conservation and use in genetic improvement. Accessions were established in a greenhouse in an open hydroponic system with volcanic sand as substrate, and under an experimental design of complete randomized blocks with five replications. Fruit quality was evaluated by assessment of physical (weight, roundness index, pulp percentage and firmness), chemical (contents of soluble solid, organic acids and vitamin C), and sensorial (color, shape, aroma, flavor and juiciness) characteristics. Using a multivariate cluster analysis, four groups of accessions were detected. A discriminant analysis corroborated the pertinence of these sets and showed that the groupings were based mainly on traits related to physical and sensorial quality. Analysis of variance and comparison of means indicated statistical differences between groups. Thus, qualities of interest with possibility of use in genetic improvement of postharvest quality were identified in the wild populations. Efficient conservation that can maintain genetic variation of the collections evaluated can be achieved by protecting 62.5% of them.