Cytological Investigations on Eight <i>Carex</i> Species in Korea (Cyperaceae)

Abstract

Carex L. is one of the most species-rich genera in the flora of Korea with about 157 taxa. Somatic or meiotic chromosome numbers of eight Carex taxa from the Korean Peninsula are reported, including first counts for C. macrandrolepis H. Lév. (n=37II) and C. splendentissima U. Kang & J. M. Chung (2n=12). Furthermore, there are first chromosomal investigations from Korea populations: C. bostrychostigma Maxim. (n=22II), C. capricornis Meinsh. ex Maxim. (n=35II), and C. breviculmis R. Br. (n=33II). None of the chromosomes has distinct primary constrictions. Carex sect. Mitratae exhibits high variation in chromosome numbers with aneuploidy (chromosome number increases with genomic duplication) and/or agmatoploidy (chromosome number increases without genomic duplication) whereas C. sect. Siderostictae shows polyploidy. Chromosome dynamics have played an important role in Carex species diversity in the Korean Peninsula.

Chromosome Counts of Six Korean <i>Carex</i> Species (Cyperaceae)

“…The chromosome number of the species varies, n=20, 27, 28, 30, 38 (Table 1). Counts in Russia (n= 40; Krogulevich 1971, n= 60;Yurtsev and Zhukova 1982) and Korea (n=27 II ; present study, Chung et al 2016, n=28 II ; present study, n=38 II ; Chung et al 2017) exhibit variation. High variation in chromosome number might be related with the broad geographic distribution of the species although the morphological variation of the species is not significant.…”

“…In addition, chromosome variation in numbers is more significant in recently derived taxa (Hipp 2007, Chung et al 2012. Incongruent taxonomic hypotheses might have resulted in diverse numbers in chromosome reports within the species (Table 1, Roalson 2008), but previous studies on Carex chromosomes such as Hipp et al (2007) and Chung et al (2017) suggest that it could be a biological phenomenon.…”

Meiotic chromosome numbers of five Carex taxa in Korea (Cyperaceae)

“…In addition, a basal linage in Carex, sect. Siderosticatae, exhibits large chromosomes (about 2-4 µm long) with small numbers (2n = 12), whereas recently diverged linages have smaller chromosomes (less than 1 µm long) with high numbers and continuous number variations (Chung et al, 2013;Yano et al, 2014;Jiménez-Mejías et al, 2016;Chung et al, 2017). In this paper, we report meiotic chromosome numbers of five Carex species from Korean populations and discuss their taxonomic, cytological significances.…”

“…Although chromosome number information is critical to understand Carex diversity, chromosome investigations on Korean Carex taxa have not been actively conducted. Among about 180 Korean native Carex, only 18 taxa have chromosome numbers reported (Kim, 2006;Lee and Kim, 2008;Chung et al, 2013;Chung et al, 2016Chung et al, , 2017Chung et al, 2018). The studies demonstrate polyploidy in Carex section Siderostictae Franch.…”

Report on the chromosome numbers of four Carex taxa in Korea (Cyperaceae)

“…As a holocentric chromosome group, chromosome number increase and/or decrease without DNA duplication and/or deletion events (agmatoploidy and symploidy) (Luceño and Guerra, 1996;Hipp et al, 2013) might cause relatively rapid speciation (Hipp et al, 2010;Chung et al, 2012;Escudero et al, 2012). Although chromosome information has been considered critical features for Carex diversity, chromosome numbers of about only 20 taxa out of 180 Korean taxa have been documented (Kim, 2006;Lee and Kim, 2008;Chung et al, 2013;Chung et al, 2016;Chung et al, 2017;.…”