ORIGINAL ARTICLE
Pollen morphology of some species of the genus
Quercus L. (Fagaceae) in the Southern Caucasus
and adjacent areas
1,
2 1 | Institute of Botany after A. Takhtajan, National Academy of Sciences of the Republic of Armenia, Yerevan,
Armenia |
2 | ROCEEH Research Centre ‘The role of culture in early expansions of humans’ of the Heidelberg Academy
of Sciences, Senckenberg Research Institute, Senckenberganlage 25, 60325 Frankfurt am Main, Germany |
Submission date: 2019-08-12
Online publication date: 2020-06-29
Publication date: 2020-06-29
Acta Palaeobotanica 2020; 60(1): 1–42
KEYWORDS
ABSTRACT
The palynomorphology of 19 modern species of the genus Quercus L. native to Armenia and adjacent
regions, including the Caucasus and Transcaucasia, the Mediterranean region (especially Turkey), as well
as Iran, Iraq and Afghanistan, was studied using light microscopy (LM) and scanning electron microscopy
(SEM). The work revealed two main types of apertures (3-zonocolpate, 3-zonocolp-porate) as well as six morphological
types of pollen based on three main types of exine ornamentation (tuberculate, verrucate, rugulate).
We suggest that two main groups of exine ornamentation developed from a common initial type. The first group
covers all species of the subgenus Quercus and also Q. suber and Q. alnifolia of the subgenus Heterobalanus. The
second group is limited to the morphological type Q. ilex (species Q. ilex, Q. coccifera, subgenus Heterobalanus).
On the other hand, the presence of widespread interspecific and introgressive hybridization within the genus
Quercus indicates an ongoing process of speciation. This also has an effect on pollen features, which are very similar
in a number of species but also vary in individual samples even within the same species. The morphological
uniformity of the pollen surface (especially for the subgenus Quercus), the presence of islets of secondary sporopollenin
on the surface of pollen grains, as well as orbicules in anthers, do not indicate general primitiveness of
representatives of this genus but most likely denote a relatively high degree of speciation activity within this group.