Pollen morphology of the genus Rubus L. I. introductory studies on the european representatives of the subgenus Rubus L.

Abstract

The results of pollen morphology studies of 9 European Rubus species are presented in this paper (<i>R. apricus</i>, <i>R. armeniacus</i>, <i>R. divaricatus</i>, <i>R. fabrimontanus</i>, <i>R. gracilis</i>, <i>R. hirtus</i>, <i>R. laciniatus</i>, <i>R. nessensis</i> and <i>R. pedemontanus</i>). The examination is made by SEM observation for first time and also by LM. All examined pollen grains are small, isopolar and tricolporate. All grains, except for <i>R. armeniacus</i> and <i>R. gracilis</i> tend to have very long colpi. Equatorial bridges constricted, make the pores unvisible in most of the species. <i>R. apricus</i>, <i>R. armeniacus</i>, <i>R. gracilis</i> and <i>R. pedemontanus</i> have the equatorial bridges stretched therefore the dark whole was only the trace of existing endoaperture. The sculpture of the grain confirms striate pattern and the orientation of the muri indicates the differences between the species; <i>R. pedemontanus</i> and <i>R. fabrimontanus</i> appear to have long, compact muri, parallelly orientated to the colpus; <i>R. nessensis</i> appears muri meandrically orientated, reminiscent of "finger prints" pattern with distinct thickenings in the place of connection and numerous narrow grooves with perforations. <i>R. hirtus</i> appears to have striate-scabrate sculpture because of granular elements (punctae) dispersed between the muri on all over the grain like the internal part of the exine. Shape and size turned out to be a poor criterion for identifying species.