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

Abstract

Carex L. (Cyperaceae) is the largest angiosperm genus in the temperate zones with more than 2,000 species worldwide. Unusual chromosome structures, called holocentric chromosomes, have been postulated to contribute to species diversity in the genus. In Korea, this genus has the greatest number of species, but chromosome information as it pertains to the taxa is mostly unknown. Here, we report meiotic chromosome numbers of five Carex taxa in Korea. The following observations are made: Carex jaluensis Kom. (n = 27 I I). Except for C. planiculmis, all of the species exhibit variations in chromosome numbers within individuals and/or taxa. The findings with regard to chromosome number diversity in Carex suggest that chromosome number variation (aneuploidy, agmatoploidy and/or symploidy) plays an important role in the richness of the species in the genus. Further cytological investigations are needed for a better understanding of sedge diversity in Korean flora.

Carex chromosome numbers from Korean populations (eight taxa)

“…) (Chung and Im, 2018). The Ulleungdo Island populations show consistent chromosome numbers within the individuals.…”

“…1B). Previous counts from Korean populations are the same (Chung and Im, 2018;Chung and Chung, 2021), but the number from Japan is different (2n = 46) (Hoshino, 1981). The species commonly occurs throughout South Korea and is morphologically and cytologically structured.…”

“…In addition, C. maackii and C. mollicula from Korean populations are the first reports, that broaden chromosome variation within taxa. Carex japonica from Ulleungdo Island populations exhibits two chromosome numbers, which differ from the chromosome (Chung and Im, 2018), 62 (Tanaka, 1937(Tanaka, , 1938(Tanaka, , 1939Okuno, 1939) (Hoshino et al, 2011), 68 (Tanaka, 1937) C. mollicula GB, Ulleung-gun, Ulleung-eup, Sa-dong-ri, 6 May 2020, Chung & Lee 7053…”