CONICET | Buscador de Institutos y Recursos Humanos

Small-sporedAlternaria have been isolated from a wide variety of food crops, causing botheconomic losses and human health risk due to the metabolites produced. Theirtaxonomy has been discussed widely, but no scientific consensus has beenestablished in this field to date. Argentina is a major exporter of agriculturalproducts, so it is essential to thoroughly understand the physiologicalbehaviour of this pathogen in a food safety context. Thus, the objective ofthis work was to characterize small-spored Alternaria spp. obtained from tomatofruits, pepper fruits, wheat grains and blueberries from Argentina by apolyphasic approach involving metabolomic and phylogenetic analyses based onmolecular and morphological characters. Morphological analysis divided the populationstudied into three groups; A. arborescens sp.-grp., A. tenuissima sp.-grp., andA. alternata sp.-grp. However, when these characters were simultaneouslyanalysed with molecular data, no clearly separated groups were obtained.Haplotype network and phylogenetic analysis (both Bayesian and maximumparsimony) of a conserved region yielded the same result, suggesting that allisolates belong to the same species. Furthermore, no correlation could beestablished between morphological species-groups and a metabolite or group ofmetabolites synthesized. Thus, the whole set of analyses carried out in thepresent work supports the hypothesis that these small-spored Alternariaisolates from food belong to the same species. Identification at species levelthrough classical morphology or modern molecular techniques does not seem to bea useful tool to predict toxicological risk in food matrices. The detection ofany small-spored Alternaria from Section Alternaria (D.P. Lawr., Gannibal, Peever& B.M. Pryor 2013) in food implies a potential toxicological risk.