The tribe Sinningieae (neotropical Gesneriaceae) comprises three genera (Sinningia, Paliavana and Vanhouttea) with a total of 75 species exhibiting bee, moth, hummingbird and bat pollination syndromes. The phylogeny of all species was inferred using five plasid non-coding DNA regions (atpB-rbcL, trnT-trnL, trnL-trnF, trnS-trnG, rpl16) and the nuclear-encoded chloroplast glutamine synthetase (ncpGS). Molecular cloning of ncpGS PCR products and infraspecific samplings revealed sequence variation within one third of the species. Allelic polymorphism of ncpGS and comparison between trees obtained from ncpGS gene and plastid regions combined were used to infer putative introgression events among Sinningieae. Based on a species-level phylogeny, evolution of floral morphology and nectar reward chemistry were reconstructed. Frequent parallelisms and reversals in pollination syndromes were observed. Specific sugar chemistries in nectar were found in species with bat and moth syndromes, whereas no significant difference in nectar composition were found in bee and hummingbird-pollinated species, thereby facilitating multiple shifts between these latter syndromes. Comparison of geographic area overlaps between sister species indicate that allopatric speciation was most common, with subsequent phenotypic changes and adaptations to pollinators.

Key words: floral evolution, Gesneriaceae, ncpGS, phylogeny, Sinningia, speciation