CONICET | Buscador de Institutos y Recursos Humanos

Cucurbita (2n = 20) is a new world genus that includes fifteen species distributed along the Americas. It has been remarked as one of the plant genus with the highest diversity in colour, shape and fruit dimensions. The only domesticated species of Cucurbita with an exclusively South American origin is C. maxima. It was cultivated by Guarani, Qom, and Charrua ethnics in the northeastern Argentina, Paraguay, Uruguay and Southern Brazil, and in Peru, Bolivia, and northwestern Andean valleys of Argentina by the pre-Hispanic communities of the southern Inca Empire. Current infraspecific classifications in the species are far from been complete. One of the most popular cultivar-group is for immature consumption (round summer squash ?zapallito?) and the species is many time referred as winter squash. An ample study was conducted along molecular markers and morphological descriptors in a set of 171 accesions from Genebanks, seed companies and own collection including entries from 21 countries. As expected a great variation was observed for fruits and seeds attributes, according to different uses and selections along domestication. Along Principal Component and Coordinate Analyzes, the wild ssp. andreana entries (22) clustered together. The two outgroup semi-dosmesticated C. ecuadorensis included were positioned intermediately between ssp. andreana and cultivated forms of C. maxima. Zapallito cultivar-group entries, which are characterized by a medium small mature fruits, white seeds and short internodes were centrally positioned, very close to accessions of Nugget, Buttercup and Turban. Big mature fruits cultivar-groups entries as Show, Hubbard, Banana and Plomo were scattered outwardly in the biplots. Zipinka cultivar-group fruits were characterized by bearing a relatively great amount of seed mass, possibly associated to an early domestication for seeds consumption.