Pollen morphology and variability of species from the genus rubus l. (rosaceae) alien and invasive in poland

Abstract

Rubus L. is one of the most species-rich and most taxonomically challenging genera in the family Rosaceae. The aim of this study was to investigate pollen morphology and the ranges of inter-and intraspecific variability of the studied Rubus alien species, as well as verify the taxonomic usefulness of these traits in distinguishing studied taxa from this genus. We analysed six quantitative pollen characteristics and the following qualitative ones: exine ornamentation, pollen outline and shape. The study was conducted on 24 samples of six alien Rubus species found in Poland. 720 pollen grains were measured in total. The most important pollen features included exine ornamentation and length of the polar axis (P). In the conducted studies there were no features of pollen indicating “invasiveness”. The results of our research fill the gap in knowledge on pollen structure in Rubus species alien to Poland and Europe. They may constitute a foundation for further research on the reproduction of these species (e.g. pollen viability and fertility), thus facilitating identification of features determining their expansive character.