Pollen Morphology of Gentiana L. (Gentianaceae) in Türkiye.

This study investigates the pollen morphology of 13 taxa of Turkish Gentiana using a statistical approach, contributing to their taxonomy. The aim is to elucidate the palynological characteristics of the taxa and to reveal their contributions to the systematic understanding of the genus Gentiana. The pollen grains are monad, radially symmetrical, isopolar, and tricolporate. The shapes of pollen grains are mostly oblate-spheroidal, occasionally subprolate, and rarely spheroidal. The polar axis ranges from 27.92 to 35.80 μm, the equatorial axis 25.33 to 35.42 μm. The ornamentation type is mostly observed as striate-perforate; however, striate-reticulate, striate, rugulate, reticulate, and rugulate-perforate types have also been observed. The result of numerical analyzes showed that Turkish Gentiana were divided into three groups. The results of PCA analysis, correlated with 84.2% ratio, showed that pollen characters grouped into three principal component. According to PCA analysis, the pollen characters to be used for cluster analysis were determined. Equatorial axis, Clt, Plg, pore diameter, mesocolpium, and apocolpium of the measured pollens are in the first principal component (explains 53.4%). Polar axis, Clg, p/e of the pollen characters are in the second principal component (explains 20.4%). Exine, intine, and Clg/Clt are in the third principal component (explains 10.4%). In conclusion, ornamentation type, polar axis, Clg, Clt, pore diameter, intine, exine, and mesocolpium have been identified as significant and distinguishing characters in taxonomy. Our results support the close relationship among some taxa (i.e., G. gelida and G. boissieri, G. verna subspecies, G. pyrenaica, and G. aquatica).