Electrophoretic analysis of Geoffroea (Leguminosae, Papilionoideae): taxonomic inferences in Argentinean populations

Abstract

The genus Geoffroea Jacq. was circumscribed to two species without varietal division. Nevertheless, in the taxonomic treatment of Argentinean dry-forest flora, on the basis of habit and foliar and floral features, it was possible to distinguish G. decorticans (Hook. & Arn.) Burkart var. decorticans from var. subtropicalis (Lillo) Burkart and to recognise intraspecific variation among the populations of G. spinosa. The purposes of the present study were to provide seed-protein data of Geoffroea species, and to analyse the relationships among them. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) was carried out on mature seeds harvested at different locations. Electrophoretic profile analysis showed outstanding differences between G. decorticans var. decorticans and var. subtropicalis and supported the view that these two taxa are less closely related than previously assumed, warranting their recognition at the varietal level. Moreover, attentive to the differences in the protein patterns from the analysed population of G. spinosa (Argentina: Chaco and Salta provinces), in addition to phenotypic differences, materials from other disjunct areas where this species grows need to be studied to verify their taxonomic status.