Palynological study on selected species from Hyacinthaceae with focus on taxonomical implications in Iran

Abstract

In this research, pollen micromorphology and ultrastructure of eight species belonging to genera including Alrawia, Bellevalia, Fessia, Muscari, Othocallis, Prospero, Puschkinia, and Zagrosia were investigated by light microscopy, scanning electron microscopy, and transmission electron microscopy. The pollen size varied among the studied species. Othocallis monanthos and Muscari neglectum had the largest and smallest pollen grains, respectively. Based on the Polar axis/Equatorial axis (P/E) ratio, Bellevalia saviczii had peroblate pollen shape and the rest were oblate. Exine ornamentation on the equatorial surface, sulcus margin exine ornamentation, and intine ornamentation in the sulcus membrane region of the pollen grains varied among the selected species of all genera. The exine layer in all genera had semitectate tectum, simplicolumellate infratectum, and discontinuous foot layer. There was discontinuous endexine in M. neglectum, Prospero autumnale, and Zagrosia persica. Alrawia bellii, P. autumnale, and Puschkinia scilloides had three intine layers in the sulcus membrane region, O. monanthos had two, and the rest of the species had one. Also, in those species with three layers in the sulcus membrane region, the outer intine layer had many channels. A dendrogram of the palynological characters grouped them into three pollen types and six pollen subtypes. The pollen types verified the phylogenetic relationships among the studied genera, whereas the pollen subtypes partly supported these relationships.