Morphological variability and genetic diversity in and (Cyperaceae) populations.

BACKGROUND

and . are sister species of the clade within the monophyletic section . 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 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 . are, morphologically and genetically, more homogenous than the populations of . . Compared to . 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 , representing 25.65% of the total variation in the taxon. Two populations of . (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 . , and correspond with the morphology of putative infraspecific taxa described by Cajander (var. and var. ).

CONCLUSIONS

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