Pollen Morphological Inter- and Intraspecific Variability in Selected Species of Rubus L. (Rosaceae)

Pollen morphology is one of the important vehicles in resolving some taxonomic problems on the family, genera or species level and has become part of the many disciplines and collaborative approaches in plant systematics and evolution. Palynological studies on the large and taxonomically highly complex genus Rubus L. have been limited, particularly concerning pollen variability. The aim of current study was to investigate the scope of inter- and intraspecific variability of the studied species based on pollen morphology, as well as verify taxonomic usefulness of pollen traits in distinguishing the studied taxa. The sixteen native Poland and Europe Rubus species were studied. Over a dozen quantitative and qualitative features of 2100 pollen (70 samples of 30 pollen each) were analyzed. Exine ornamentation and pollen size proved to be most useful pollen traits in the assessment of variability in the studied Rubus species. Pollen traits did not confirm the currently adopted taxonomical division of the genus Rubus into subgenera, sections and series. The greatest interspecific variability was found for traits P, E, Le and d, while variability was lowest in the case of Exp, Exe, P/E, Le/P, d/E, Exp/P and Exe/E. Intraspecific variability was determined by the following features ordered from those least to most variable: P, E, d, Le, d/E, Exp/P, Exp, P/E and Le/P.

Automated summary

Pollen morphology is an important tool in plant systematics and evolution, and can help in resolving taxonomic problems. This study focused on the pollen morphology of the genus Rubus, and found that exine ornamentation and pollen size were the most useful traits for assessing variability. However, the study did not support the currently adopted taxonomical division of Rubus. Interspecific variability was highest for traits P, E, Le, and d, while intraspecific variability was determined by traits P, E, d, Le, d/E, Exp/P, Exp, P/E, and Le/P.