The micromorphological investigation of pollen grains of Hedera L. (Araliaceae)

The palynomorphological characteristics of ۵ species belonging to Hedera of the Araliaceae family were studied in detail. These plant species were collected from various phytogeographical regions of Iran and Central Europe. The palynological investigation was accomplished using Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM). Pollen grains of the species are reticulate, prolate, sub-prolate, tricolporate, isopolar, radially symmetrical, and monad. The largest pollen grain was in the Hedera colchica species (۶۰.۹۹±۲.۸ μm) and the smallest pollen grain was in Hedera helix (۲۸.۶۳±۲.۱ μm). The research carried out by the TEM showed that the species were different in terms of Exin thickness,Tectum thickness, Foot layer thickness, the diameter and length of the Columellae, the thickness and shape of the Caput, the tectum to footl ayer ratio )T/F(, the absence or presence of the Endexine and the thickness of the Intine layers. Observed differences were not of diagnostic importance in species level. The main aim of this study was to find distinguish pollen characters in the species of the genus Hedera and to elucidate their systematics importance

کلیدواژه ها:

Systematics ، TEM ، Iran ، SEM ، Eexin