Studies on Neotropical Gesneriaceae: palynotaxonomy in Columneinae (Core columneinae and Paradrymonia alliance)

Abstract

The palynology of Gesneriaceae, especially of Brazilian species, has been analyzed in recent years and the results of these studies have helped in the morphological definition of genera and in the distinction of species or groups of species, confirming the importance of palynology as a morphological tool for taxonomic studies. Columneinae is the largest and most diverse subtribe of Gesnerieae. Its genera are usually characterized by a combination of symplesiomorphic characters, which consequently generates the formation of unnatural groups, requiring deeper studies of the morphological and molecular characteristics of the representatives of the subtribe. The pollen morphology of 117 neotropical species of Columneinae belonging to the Core Columneinae and the clade "Paradrymonia alliance" will be studied in order to describe the morphology of the pollen grains, thus expanding the knowledge about pollen diversity in the genera studied and providing characters to define clades for a better understanding of the relationships among them. The pollen grains will be acetolysed, measured and photographed under light microscopy, and pictures will be taken using scanning electron microscopy to observe the exine ornamentation as well as transmission electron microscopy to characterize the pollen grain's ultrastructure. Quantitative data will receive appropriate statistical analysis according to sample size and in order to identify the discriminating pollen characters for species identification, a multivariate analysis will be performed. Qualitative data will be described and grouped into pollen types, contributing to species identification and understanding of the evolution of the group. (AU)