POLLEN MORPHOLOGY OF SAPONARIA L. (CARYOPHYLLACEAE) SPECIES AND ITS TAXONOMIC VALUES

In this research pollen morphology of ten taxa (5 of them endemics) that belong to the genus Saponaria L. in Iran were investigated using scanning electron microscope (SEM). In order to study the pollen morphology of Saponaria and find its significance in taxonomy of the group, qualitative and quantitative variables of pollen characters related to the shape, size, ornamentation and pores were studied. Cluster and Principal Component Analysis (PCA) of qualitative and quantitative data were used to demonstrate the pollen grains similarities among the species. According to the results, pollen type of Saponaria species is polyporate and displays either peroblate, polyhederal and spheroidal pollen shapes. Pollen size also varies among different species. The longest polar axis length belongs to S. officinalis L. (51.03 µm) and the smallest one to S. floribnuda (Kir. & Kar.) Boiss. (22.82 µm). Pore ornamentation differs from prominent granular to slightly protuberant or distinctly sunken granular (deeply excavated). The pollen ornamentation is microechinate-punctate in all species except in S. esfandiarii which has microechinate ornamentation and lacks puncta. Based on the results, the morphological characters of the studied pollen grains have taxonomic value in distinguishing taxa at the species level.