Palynomorphological Observations on the Genus Sabulina Rchb. (Caryophyllaceae) from Turkey Using Light Microscopy and Scanning Electron Microscopy.

Abstract

Pollen morphology of 28 taxa belonging to the genus Sabulina Rchb. (Caryophyllaceae) from Turkey was examined and compared using light microscopy and scanning electron microscopy. The current study aimed to describe the palynological characteristics of the Sabulina taxa and to assess the diagnostic value of these features for taxonomic implications. The pollen grains of Sabulina are radially symmetrical, apolar, rarely isopolar, and pantopolyporate with 8-28 pores. Their shape is prolate-spheroidal with the A axes (long axes) 19.5 μm and the B axes (short axes) 19-39.5 μm. Exine sculpturing is microechinate-punctate in all taxa. Principal component analysis was used to evaluate the significant pollen morphological characters for distinguishing the taxa, with three components accounting for 95.112% of the total variance. Numerical analysis revealed that pollen sizes, pore diameters, pore numbers, distance between pores, spinule density, and punctum numbers are particularly the most useful variables for separating the Sabulina taxa. The results also display a partial relationship between the Sabulina taxa clusters based on pollen morphology and the systematics of these taxa based on general macromorphology.