Palinotaxonomy in Brazilian species of Ligeriinae Hanst. (Gesneriaceae)

Abstract

Gesneriaceae, as well as much of the angiosperms, had its systematic and phylogeny revised in recent years based primarily on molecular data, together with previously performed morphological research. The palynology is a morphological tool widely used in taxonomic studies, data from pollen grains and the definition of pollen types may improve the delineation of genera, subgenera or related groups of species. Thus, the aim of this study is to describe the pollen morphology of 50 Brazilian species of Ligeriinae Hanst., and two species of Sphaerorrhizinae A.Weber & J.K.Clark, contributing to the morphological characterization of species, identifying pollen data that can help the taxonomy of the group, increasing knowledge about pollen diversity in the genera and providing subsidies to a better understanding of the relationships between genera of the subtribe Ligeriinae (Gesnerieae - Gesneriaceae) and its sister group, the monogeneric subtribe Sphaerorrhizinae. 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 grains 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)