Abstract
Counting chromosomes is the first step towards a better understanding of the karyotype evolution and the role of chromosome evolution in species diversification within Carex; however, the chromosome count is not known yet for numerous sedges. In this paper chromosome counts were performed for 23 Carex taxa from Armenia, Austria, the Czech Republic, and Poland. Chromosome numbers were determined for the first time in three species (Carex cilicica, 2n = 54; C. phyllostachys, 2n = 56; C. randalpina, 2n = 78), two subspecies (C. muricata subsp. ashokae, 2n = 58; C. nigra subsp. transcaucasica, 2n = 84) and two hybrids (C. ×decolorans, 2n = 74; C. ×walasii, 2n = 108). Among the taxa whose number of chromosomes had been known before, the largest difference was found in C. hartmaniorum (here 2n = 52) and C. aterrima subsp. medwedewii (here 2n = 52). A difference in the chromosome count was demonstrated for C. cilicica (2n = 54) versus the species of the section Aulocystis (2n = 30 to 40) and for C. tomentosa (2n = 48) versus the species of the section Acrocystis (2n = 18 to 38). The results of this study indicate that the position of C. cilicica in Aulocystis section may raise doubts. Attention was paid to the relationship between C. phyllostachys and taxa of the subgenus Carex section Gynobasidae.
Highlights
With about 2000 species described worldwide Carex L. (Cyperaceae) represents one of the most species-rich angiosperm genera [1]
The situation is different with holocentric chromosomes, because chromosome fragments are not lost, and a change in the chromosome count can be offset by, e.g., self-pollination or back-crossing
This paper is the first to provide chromosome numbers for seven Carex taxa belonging to five sections (Table 1)
Summary
With about 2000 species described worldwide Carex L. (Cyperaceae) represents one of the most species-rich angiosperm genera [1]. With about 2000 species described worldwide Carex L. (Cyperaceae) represents one of the most species-rich angiosperm genera [1]. The taxonomic richness is accompanied by an extreme variability in the number of chromosomes [2]. Sedges have holocentric chromosomes, which–in theory–guarantee a rapid karyotype evolution [3,4]. If a monocentric chromosome is fragmented, fragments lacking the centromere cannot be normally segregated during meiosis, which results in a loss of genetic material, the gametes produced being potentially non-viable [3]. The situation is different with holocentric chromosomes, because chromosome fragments are not lost, and a change in the chromosome count can be offset by, e.g., self-pollination or back-crossing.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
