Taxonomical Relations of Tribe Lilieae (Liliaceae) Based on palynological Issues

Abstract

ABSTRACT Pollen micromorphology and ultrastructure of fifteen species from the genera Cardiocrinum, Fritillaria, Lilium, and Notholirion were examined by Light Microscopy (LM), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). Our results showed that all quantitative characters of pollen micromorphology (LM and SEM observation) varied in the studied taxa. Pollen grains in all studied species were oblate except Notholirion bulbuliferum with oblate-spheroidal. The studied species of Fritillaria had medium pollen type and the rest showed large. Although, two major exine ornamentation in central region of equatorial surface and sulcus margin region were seen such as reticulate (taxa of Cardiocrinum) and reticulum-cristatum (taxa of genera of Lilium, and Notholirion). These characters were varied in taxa of Fritillaria in both regions (foveolate-rugulate, reticulate and foveolate). Also, there were three sulcus membrane ornamentation including striate-tuberculate (Fritillaria gibbosa), tuberculate (Lilium lophophorum and with the rest studied taxa of Fritillaria), and macrotuberculate (the genera Cardiocrinum, Lilium, and Notholirion). Moreover, three kinds of lumina types and two kinds of muri types were detected among these taxa. The qualitative and quantitative characters of the pollen wall were varied such as kind of endexine situation, number of intine layers in the sulcus membrane region, and thickness of elements from the pollen wall. Dendrogram of all qualitative and quantitative palynological characters constructed two pollen groups, five pollen types, and four pollen subtypes. The palynological dendrogram verified that Nomocharis is part of genus Lilium. Palynological types supported the heterogeneous phylogenetic situation of Cardiocrinum. Palynological subtypes were partly valuable in delimitation of sectional levels of the genus Lilium.