Pollen micromorphology of the selected taxa of the genus Dianthus (sect. Fimbriati) in Iran

The genus Dianthus L. (Caryophyllaceae) with approximately ۶۰۰ species, is one of the important genera of the family, distributed across Europe, Asia, and Africa. This study aimed to investigate and characterize the pollen diversity of ۱۴ taxa of the genus Dianthus (sect. Fimbriati) from various regions of Iran, with the objective of providing further insight into taxonomic and identification challenges within this group based on palynological data. The pollen grains were studied using light microscopy (LM) and scanning electron microscopy (SEM). Eighteen pollen characteristics such as size, shape, surface ornamentation, type and number of apertures, and their dimensions were examined. The data were analyzed using Past software and phylogenetic trees were constructed. The results showed that, D. libanotis and D. orientalis subsp. gorganicus were distinguished by their unique features for instance the distance between the pores (G) separated D. libanotis, while the large polar diameter (B), small equatorial diameter (C), and number of pores (M) differentiated D. orientalis subsp. Gorganicus from other taxa. Pollen heteromorphism in both size and shape was reported here for the first time within the Caryophyllaceae. Results from PCA and clustering analyses of pollen characteristics were consistent and supported each others. The study also revealed that, polar diameter, equatorial diameter, distance between pores and number of pores are among the most significant variables for distinguishing of the studied taxa. This is the first comprehensive study on pollen grains of this genus in Iran.

کلیدواژه ها:

Caryophyllaceae ، Dianthus ، micromorphology ، Phylogenetic tree ، pollen grain ، Systematics