PROTEOMICS OF GENETIC DIVERSITY IN RELATION TO TOMATO FRUIT SIZE

Abstract

The varieties of domesticated tomato (Lycopersicon esculentum) exhibit large phenotypic variability (size, color and organoleptic traits). However, the molecular polymorphism of DNA markers is very low. In this study we used proteomic approach to investigate the genetic diversity within the species of the Lycopersicon genus. A collection of nineteen phenotypically well characterized varieties of L. esculentum, representing all tomato size classes, and one accession of each eight wild species were analysed. Proteins of the tomato pericarp were separated by two-dimensional gel electrophoresis. The qualitative and quantitative spot differences between tomato varieties were investigated and main protein variations were pointed out. Proteomics gave access to protein polymorphism between genotypes of L. esculentum. 162 of 1300 reproducible spots, varied among the nineteen varieties of L. esculentum at red-ripe stage. Protein identification by mass spectrometry showed that most of these proteins are associated with stress response, metabolism and development. For the wild species the degree of polymorphism was much higher.