• Korean Journal of Plant Taxonomy
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• v.49 no.4
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• pp.334-344
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• 2019

The genome size is defined as the amount of DNA in an unreplicated gametic chromosome complement and is expressed as the 1C value. It is a fundamental parameter of organisms that is useful for studies of the genome, as well as biodiversity and conservation. The genome sizes of Korean plants, including Carex (Cyperaceae), have been poorly reported. In this study, we report the genome sizes of 43 species and infraspecific taxa of Korean Carex using flow cytometry, and these results represent about 24.4% of the Carex species and infraspecific taxa distributed on the Korean peninsula. The Plant DNA C-Value Database (release 7.1) updated with and now including our data (a total of 372 Carex accessions) shows that the average genome size of members of the Carex species is 0.47 pg (1C), and the largest genome (C. cuspidate Bertol.; 1C = 1.64 pg) is 8.2 times larger than the smallest (C. brownii Tuck., C. kobomugi Ohwi, C. nubigena D. Don ex Tilloch & Taylor, and C. paxii Kuk.; 1C = 0.20 pg). The large genomes are frequently found in the subgen. Carex, especially in sect. Aulocystis, sect. Digitatae, sect. Glaucae, sect. Paniceae, and sect. Siderostictae. Our data updates the current understanding of genome sizes in Carex. This will serve as the basis for understanding the phylogeny and evolution of Carex and will be especially useful for future genome studies.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.247-255
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• 2014

Objectives: We reviewed the CAREX (CARcinogen EXposure) program designed to estimate the prevalence of occupational exposure to carcinogens and summarized the advantages and limitations of this program. Methods: All literature, including reports on CAREX and the use of CAREX, were reviewed. The keyword search term was CAREX. Additional articles were identified from references cited in articles and reviewed. Results: An exposure information system, CAREX was developed based on data from the Finnish Institute of Occupational Health of Finland and from the US. CAREX has been applied in several countries, including in the EU, in order to estimate national exposure patterns to carcinogens. The initial exposure assessment carried out through CAREX was aimed at estimating exposures over the period of 1990-1993. To estimate the number of workers exposed to carcinogens by using CAREX, reference exposure prevalence from Finland and the United States was computed, which was then reviewed and corrected by national experts. Finally the overall number of workers exposed to carcinogens can be estimated. We found that CAREX has been used in a total of 18 countries. No Asian country has used CAREX. Conclusions: CAREX can be applied not only to estimate the number of workers exposed to carcinogens in Korea, but also to identify high-risk industries with workers most exposed to carcinogens.

• Korean Journal of Plant Taxonomy
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• v.50 no.3
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• pp.361-367
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• 2020

We report meiotic chromosome numbers of three taxa in Carex sect. Mitratae in Korea: Carex breviculmis R. Br. (n = 32_II, 33_II, 34_II), C. polyschoena H. Lév. & Vaniot (n = 37_II, 38_II), and C. sabynensis Less. ex Kunth (n = 27_II). Section Mitratae is one of the most species-rich Asian groups in Carex, comprising approximately 45-80 taxa. Twenty-seven of these occur in Korea, and they are some of the most challenging taxa to identify due to their obscure and inconspicuous diagnostic characters. Including the counts reported here, half of the native Korean sect. Mitratae chromosome numbers have been documented. Their haploid chromosome numbers range from n = 10 to n = 40, and many exhibit variations in the numbers counted within a taxon. These variations, along with the overall significant variation in sect. Mitratae, suggest that dynamic chromosome activity may be related to the high species diversity of Carex.

• Korean Journal of Plant Taxonomy
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• v.51 no.3
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• pp.192-197
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• 2021

In the flora of Korea, Carex L. is one of the most species-rich genera. Among nearly 157 Carex taxa, less than 30 have had chromosome numbers reported. We report the meiotic chromosome numbers of eight Carex taxa from Korean populations, which include the first count for C. accrescens Ohwi (n = 37_II) and the first chromosome investigations of Korea populations for three taxa: C. bostrychostigma Maxim. (n = 22_II), C. lanceolata Boott (n = 36_II), and C. paxii Kuk. (n = 38_II). In most species, chromosome counts observed in the study are included in the variation ranges of previous chromosome numbers. However, C. bostrychostigma Maxim. (n = 22_II) and C. planiculmis Kom. (n = 29_II) are assigned new chromosome numbers. Carex is known to have holocentric chromosomes, lacking visible primary constrictions and exhibiting great variance in its chromosome number. Further investigations of the diversity of Carex chromosomes will provide basic information with which to understand the high species diversity of the genus.

• Korean Journal of Plant Taxonomy
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• v.49 no.3
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• pp.269-273
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• 2019

We report the meiotic chromosome numbers of four Carex taxa from Korean populations. Three are the first reports made on taxa from Korean populations: Carex appendiculata (Trautv. & C. A. Mey.) $K{\ddot{u}}k$. ($n=27_{II}$), C. fernaldiana H. $L{\acute{e}}v$. & Vaniot ($n=33_{II}$), and C. metallica H.$L{\acute{e}}v$. ($n=15_{II}$). Reports on the other species expand the range of variation in the chromosome number within a taxon, C. miyabei Franch. (n = $43_{II}$, $44_{II}$, $45_{II}$). Carex L. (Cyperaceae) consists of more than 2,000 species worldwide and is the most species-rich genus in Korea. The species diversity in the genus has been hypothesized to be associated with the chromosome variation, but chromosome information pertaining to Korean Carex taxa is not well known. This report updates the chromosome number inventory on Korean Carex to 24 out of 180 taxa.

• Korean Journal of Plant Taxonomy
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• v.42 no.4
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• pp.275-277
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• 2012

Carex kamagariensis K. Okamoto was found in throughout the nation. This species is distinguished from other related taxa in Carex sect. Mitratae by pistillate scales with a long arista and achenes constricted above in the middle. A new Korean name, 'Jom-mok-po-sa-cho', is based on its small size and floral character similarity to C. genkaiensis. In this study, a description, illustrations and habitat photos of the species are provided. The key of its related species is also provided.

• Journal of Life Science
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• v.10 no.1
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• pp.52-60
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• 2000

Up to now, there have been done much efforts in regard to nitrate reductase activity (NRA) of dicotyledonous herbs and important crop monocotyledons, but few to wild plants having canopy structure such as Carex. The objective of the present study are to determine: a) the optimum in vivo NR assay conditions for leaf samples of Carex species, b) changes of NRA according to section within leaf and leaf ages, c) diurnal variations. Optimized assay media of each Carex species were determined. NRA of C. rostrata adapted to oligotrophic habitats is readily saturated at lower substrate concentration than those of C. distans and C. gracilis, adapted to meso- and eutrophic habitats, respectively. All Carex species investigated have higher NRA in leaves than in roots. NRA of all species showed maximal values at the middle section of each leaf and in the youngest fully expanded leaves. Compared to C. gracilis, NR in leaves of C. distans was adapted readily to the light period. On the whole, Carex showed rather delayed diurnal variation. Even if the in vivo nitrate reductase assay based on nitrite estimation does not give an accurate estimation of total nitrate reduced, it still serves as a useful tool to find out relative differences in varying environmental conditions. Additionally, in vivo RNA measurements are helpful to understand nitrate reduction and basic nitrogen metabolism of Carex species having different canopy structure.

• Korean Journal of Plant Taxonomy
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• v.43 no.1
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• pp.22-26
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• 2013

We report somatic chromosome numbers 2n = 12 for three Carex sect. Siderostictae Franch. ex Ohwi (Cyperaceae) from Korean populations: Carex ciliatomarginata Nakai, C. okamotoi Ohwi, and C. siderosticta Hance. This study is the first chromosome number report for the species C. ciliatomarginata from Korean populations. As found in other Carex species, all the chromosomes examined in the section exhibit nonlocalized centromere (polycentric or holocentric) and large (more than ca. $1{\mu}m$ long) chromosomes. Considering the basal phylogenetic position of the section in tribe Cariceae Pax, small numbers of large chromosomes have been hypothesized as primitive characters in Cariceae, and our observation supports the hypothesis. Further investigations of chromosomes in Carex are needed for a better understanding of species richness in the genus.

• Korean Journal of Plant Taxonomy
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• v.42 no.4
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• pp.335-339
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• 2012

An unrecorded species, Carex benkei T. Shimizu, was found in Is. Jaewondo, Jaewon-ri, Imja-myeon, Sinan-gun, Jeollanam-do and Dongbaik-dongsan, Seonheul-ri, Jocheon-eup, Jeju-si, Is. Jeju-do, South Korea. C. benkei is closely related to C. transversa Boott and C. brownii Tuck., and C. benkei is distingushied from the pistillate scales length, excluding the awn, similar to the achene and the beak of the achene with an annular appendage. A new Korean name, 'Gin-Hwa-Sal-Sa-Cho', was given based on its long pistillate scales excluding the awn compared with Carex transversa Boott. We provide here its redescription, illustrations, photographs, and a key to species of the sect. Confertiflorae Franch. ex Ohwi.

• Korean Journal of Plant Taxonomy
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• v.44 no.4
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• pp.247-249
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• 2014

A newly naturalized plant, Carex scoparia Schkuhr ex Willd. var. scoparia, was found in Mt. Hanseok, Injegun, Gangwon-do, Korea. It belongs to sect. Ovales Kunth and had been known from North America, and was introduced into Europe and New Zealand. This species distinguished from related taxa in Asia, Carex maackii Maxim. and Carex leporina L., by pistillate scales lanceolate and having large perigynia. We propose the new Korean name, 'Han-seok-sa-cho', based on its first collecting place. We also provide descriptions for morphological characters, illustrations, photographs and keys to allied taxa.