Pollen Morphology of Rosa sericea Complex and Their Taxonomic Contribution

In this research, the pollen morphology of the Rosa sericea complex has been studied by Scanning Electron Microscope (SEM). The present study aimed to provide baseline information for the taxonomic identification of the R. sericea complex taxa. The pollen sculpture, outline, and aperture show variability in the studied taxa. The R. sericea complex includes taxonomically challenging species with undistinguishable boundaries. Identifying taxon boundaries in closely related species is fundamental to investigating evolution and biodiversity. Taxa circumscription of R. sericea complex is insufficient, unresolved, and is a prerequisite for comprehensive systematic revisions. To resolve these issues, we have attempted to identify some important diagnostic characters for the species of R. sericea complex. This research studied different qualitative and quantitative characteristics of R. sericea complex pollen. The qualitative characteristics included polar and equatorial view, sculpture, pollen outline, apertures, exine, size category, and polarity of pollen. In contrast, the quantitative features include polar and equatorial diameter, P/E, colpi length and width, and distance between colpi. Pollen of this complex is mono and tricolporate. The morphological characters studied here provide very few taxonomic details with which to separate the species of the complex into distinct taxa. Some of the studied characters offer important information for species delimitation including sculpture, pollen outline, and apertures.