Morphological variability and genetic diversity in Carex buxbaumii and Carex hartmaniorum (Cyperaceae) populations

Helena Więcław; Magdalena Szenejko; Thea Kull; Zofia Sotek; Ewa Rębacz-Maron; Jacob Koopman

doi:10.7717/peerj.11372

Morphological variability and genetic diversity in Carex buxbaumii and Carex hartmaniorum (Cyperaceae) populations

PeerJ. 2021 May 11:9:e11372. doi: 10.7717/peerj.11372. eCollection 2021.

Authors

Helena Więcław¹, Magdalena Szenejko^{1

2}, Thea Kull³, Zofia Sotek¹, Ewa Rębacz-Maron⁴, Jacob Koopman⁵

Affiliations

¹ Institute of Marine and Environmental Sciences, University of Szczecin, Szczecin, Poland.
² Molecular Biology and Biotechnology Center, University of Szczecin, Szczecin, Poland.
³ Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Tartu, Estonia.
⁴ Institute of Biology, University of Szczecin, Szczecin, Poland.
⁵ Unaffiliated, Choszczno, Poland.

Abstract

Background: Carex buxbaumii and C. hartmaniorum are sister species of the clade Papilliferae within the monophyletic section Racemosae. An unambiguous identification of these species is relatively difficult due to the interspecific continuum of some morphological characters as well as the intraspecific variability. The study was aimed at determining the range of variability, both morphological and genetic, within and between these two closely related and similar species.

Methods: The sedges were collected during botanical expeditions to Armenia, Estonia, the Netherlands, and Poland. The morphological separation of the two species and their populations was tested using the Discriminant Function Analysis (DFA). The genetic variability of the 19 Carex populations was assessed in the presence of eight Inter Simple Sequence Repeat (ISSR) primers.

Results: Results of the study indicate a considerable genetic affinity between the two sedge species (mean Si = 0.619). However, the populations of C. hartmaniorum are, morphologically and genetically, more homogenous than the populations of C. buxbaumii. Compared to C. hartmaniorum, C. buxbaumii usually has wider leaf blades, a shorter inflorescence, a lower number of spikes which are shorter, but wider, and longer bracts and utricles. The AMOVA showed a larger variation between the populations of C. buxbaumii, representing 25.65% of the total variation in the taxon. Two populations of C. buxbaumii (from Poland and Estonia) are separated from the remaining populations, both genetically and morphologically; their individuals show shorter utricles and glumes, compared to the typical specimens of C. buxbaumii, and correspond with the morphology of putative infraspecific taxa described by Cajander (var. brevisquamosa and var. confusa).

Conclusions: The taxonomic status of the putative infraspecific taxa within C. buxbaumii requires further studies throughout the distribution range of C. buxbaumii, addressing habitats, morphology and genetics (including a chromosome count or a combination of different genetic methods), particularly as the variability in C. buxbaumii may be associated with the species' polyploid origin.

Keywords: Discriminant function analysis; Genetic affinity; ISSR polymorphism; Intra- and interpopulation variability; Phenotypic plasticity; Racemosae.

Grants and funding

The authors received no funding for this work.