Checking the status of infraspecific taxa within Galactia jussiaeana (Fabaceae) using Berg's correlation-pleiades hypothesis

Abstract

Berg's correlation-pleiades hypothesis proposes that phenotypic variation between plant vegetative and reproductive traits is decoupled (i.e. varies independently) due to different selective pressures: pollinators in reproductive traits and environment in vegetative traits. We used this hypothesis to check if the intraspecific leaf variation in Galactia jussiaeana is accompanied by an equal variation in floral traits. If so, we might be facing a process of divergence between the two lineages, since differences in floral morphology could restrict gene flow due to a mismatch with pollinators. Our results showed that there was no correlation between the variation in vegetative and reproductive traits in G. jussiaeana var. angustifolia, demonstrating that both are genetically uncoupled and respond to different selective pressures. There were also no significant differences in reproductive structures between the alternative and the typical variety. For these reasons, we propose the synonymization of G. jussiaeana var. angustifolia under G. jussiaeana.