METABOLIC PATTERNS FOR QUALITY TRAITS IN TOMATO FRUITS

ESTER MARINA INSANI; MARIA F GODOY; PABLO CORTINA; RAMON ASIS; IRIS PERALTA; ANA SANTIAGO; FERNANDO CARRARI

German Nutrition Society

Conferencia; 12th European Nutrition Conference (FENS); 2015

Introduction: Tomato (Solanum lycopersicum) is one of the most widely consumed fruit and consequently germplasm selection is a very intense process. However, small farmers have preserved part of the gene pool by heritage and tradition. Complex regulatory pathways of primary and secondary metabolism impact on the nutritional and sensory properties of the fruits. Thus, the variability found in landraces offers new sources that can be exploited in breeding programs aimed to enhance these traits.Objectives: To identify quality traits in local tomato accession by integrating different metabolite profile analyses.Method / Design: 52 tomato varieties were evaluated including landraces commercial cultivars and reference genotypes (M82 ?S. lycopersicum- and LA1589 ?S. pimpinellifollium, wild specie-), cultivated under field conditions. Ripe fruits were profiled by GC-MS to identify and quantify (in relative terms) primary (PMets) and volatile (VMets) metabolites. Non-parametric statistical analyses were applied.Results: 90 different PMet compounds were identified. Among organic acids, pyroglutamic, butyric acid, 4-amino (GABA), dehydroascorbic and malic were those showing the higher variability within cultivars. In the case of sugars, sucrose showed changes of 250X. Analytes of unknown identity also presented marked variability among different cultivars. PCA and HCA of PMets and 47 VMets were efficient to classify the genotypes by their morphology (round, elongated and cherry). The elongated cultivars stand up for the content of some aminoacids , while cherries showed more abundance of unknown metabolites. Spearman correlation analyses showed positive correlation (r>0.8) of glutamine metabolism with the VMets 3-methyl-1-butanol and 3-methylbutanal and negative correlation with heptanal. Glutamic acid pathway appears as a critical point of divergence because both, this aminoacid and GABA were highly variable in the analyzed varieties. VMets from the butanoate metabolism also showed high variability.Conclusions: Metabolic profiles resulted in valuable tools to identify quality traits in tomato fruits for breeding purposes.