• Korean Journal of Ichthyology
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• v.18 no.3
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• pp.155-162
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• 2006

The chromosome numbers of five species in two families of Korea are investigated: Odontobutis platycephala, O. interrupta, and O. obscura in Odontobutidae, and Cottus koreanus and C. hangiongensis in Cottidae. In Odontobutis species, the three species showed the diploid chromosome number, 2n=44 (NF=44) telocentric chromosomes. In Cottus species, the mitotic chromosomes from 24 groups with two chromosomes each indicated that it is a diploid. The karyotype of C. koreanus and C. hangiongensis is 2n=48 and NF=52. These species is the first report on the chromosomes and the karyotype analysis except O. platycephala. Our findings provide cytotaxonomic evidence for the species distinctness of these five species whose descriptions were based primarily on external morphology.

• The Korean Journal of Zoology
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• v.2 no.2
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• pp.15-24
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• 1959

Concluding the result of this observation, authors obtained the table showing chromosome numbers which are consisted in each species as follow. Viewing on this result, authors recognized Acrididae are determined the sex with X-O type. 6 species of Family Acrididae and one species of Family Gryllotalpidae (on above table) had already calculated the number of chromosomes by some foreign observers. But another one species (Briodema tuberculatum dilatum STOLL) clarified by authors firstly in this observation. In 2nd spermatocyte of Trilophidia annulata YHUMBERG 1 to 3 Ist constriction satellites were observed, and each of the small bodies was connected with thin fibre and constituted with same or less breadth as the main chromosomes. If those are not the satellites, they should be the super-numerary chromosomes appearing a dot form. In this observation, among 48 species of Family Acrididae which have been found in Korea 18 species were calculated their chromosome numbers which were including 1 species calculated by authors newly. And authors have reobserved the chromosomes of Gryllotalpa africana PALISOT de BEUVOIS of Family Gryllotalpidae which was done by Japanese before.

• Korean Journal of Plant Resources
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• v.22 no.6
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• pp.506-512
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• 2009

To study the effect of genotype of donor plants on anther culture, anthers of nine hybrid cultivars (Derby, Special, Bossanova, Minipaprika, Fiesta, Boogie, Phenlene, Kufrah, and Clarity) of sweet pepper (Capsicum annuum L.) were cultured in a petridish containing C medium (Sibi, Dumas De Vaulx medium) supplemented with 0.1 mg/L 2,4-D and 0.1 mg/L kinetin, 3% sucrose and 0.32% Phytagel. The cultures were incubated in the dark at $35^{\circ}C$ for seven days, and then cultured at $25^{\circ}C$ with a photoperiod of 16 hr. daylength for 40 days. Frequency of callus formation and plant regeneration was varied among cultivars. Callus formation was ranged from 6% in Phenlene to 69.8% in Kufrah. The highest percentage of regenerated plantlets was obtained in cv. Phenlene (2.67%) followed by Bossanova (2.41%). Result of ploidy analysis; chromosome number observation and flowcytometry analysis, showed that haploid plants could be developed from all of these hybrid cultivars except cv. Fiesta, where highest percentage of haploid plants were obtained in Minipaprika (40%) followed by cv. Bossanova (36.1%). Haploid plants derived from these hybrid cultivars contained single set of chromosome (12 in numbers), higher stomata density (numbers), and smaller sized stomata as compare to diploid plants. The mean length of stomata was 26.9 ${\mu}m$ in haploid plants and 35.7 ${\mu}m$ in diploids.

• Korean Journal of Plant Tissue Culture
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• v.28 no.2
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• pp.113-116
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• 2001

Chromosomal variation was investigated in the female and male somaclones regenerated from the leaf segment culture of Rumex acetosa L. Difference in phenotype depending on the sexuality was not observed. In female somaclones, 21 among 25 somaclones carried the same chromosome complements (2n＝14) with wildtype and others were tetraploids (2n=28), Considerable chromosomal variation was found in male somaclones. Only 4 among 20 somaclones carried normal chromosome number (2n=15) and 13 somaclones were aneuploids.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.3
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• pp.171-175
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• 1992

In 1991, specimens of the arkshell, Scapharca broughtonii of Arcidae(Ptriomorphia, Mollusca) were collected from bottom culture bed at Namhae Island in Korea. The chromosomes were examined in the colchicinetreated cells of trochophore larva based on the air-drying method. Diploid number of the chromosome was 38 which were classified as metacentrics(pairs 5, 8, 13), meta or submetacentrics(pairs 6, 7), submetacentrics(2, 3, 9, 10, 12, 15, 16, 17, 18, 19) and subtelocentrirs(pairs 1, 4, 11, 14). No telocentric chromosome was observed.

• Korean Journal of Agricultural Science
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• v.50 no.2
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• pp.193-206
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• 2023

Orchidaceae species account for one-tenth of all angiosperms including more than 30,000 species having significant ecological, evolutionary, and economic importance. Despite Orchidaceae being one of the largest families among flowering plants, crucial cytogenetic information for studying species diversification, inferring phylogenetic relationships, and designing efficient breeding strategies is lacking, except for 10% or less of orchid species cases involving mostly chromosome number or karyotype analysis. Also, only approximately 1.5% of the identified orchid species from less than a hundred genera have genome size data that provide crucial information for breeders and molecular geneticists. Various molecular cytogenetic techniques, such as fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH), have been developed for determining ploidy levels, analyzing karyotypes, and evaluating hybridity, in several ornamental crops including orchids. The estimation of genome size and the determination of nuclear DNA content using flow cytometry have also been employed in some Orchidaceae subfamilies. These different techniques have played an important role in supplementing beneficial knowledge for effective plant breeding programs and other related plant research. This review focused on orchid breeding summarizes the status of current cytogenetic tools in terms of background, advancements, different techniques, significant findings, and research challenges. Principal roles and applications of cytogenetics in orchid breeding as well as different ploidy level determination methods crucial for breeding are also discussed.

• Horticultural Science & Technology
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• v.16 no.3
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• pp.361-363
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• 1998

Cymbidium goeringii native to Korea and other orchid plants were pot-grown from spring to autumn under the greenhouse conditions, and were subjected to artificial pollination to elucidate the compatibility by revealing viable seed formation. A notable compatibility was found when Cym. goeringii was selfed and was crossed with either Cym. ensifolium, Cym. kanran, Cym. sinense, Cym. sinense for. albo-jucundissimum, Cym. 'Crystal Cherry Angel', or Cym. 'Anmitsu Hime'. Cym. goeringii, however, did not show such compatibility when crossed with either Cym. faberi, Cym. aloifolium, Dendrobium chrysotoxum, or Phalaenopsis spp. RAPD analysis indicated that taxa relationship between Cym. goeringii and either Cym. faberi or Cym. aloifolium (respective chromosome number, 2n=40) was distant, showing no compatibility, and even more distant in the case of cross-pollination between Cym. goeringii and either Dendrobium chrysotoxum or Phalaenopsis spp. having different chromosome number from all Cymbidium species.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.4
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• pp.67-72
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• 2004

This paper proposes a method improving the convergence speed of optimal solution for parallel genetic algorithm in the network based client-server model. Unlike the existing methods of obtaining global elite only by evaluating local elites in server, the proposed method obtains it by evaluating local elites and improving its fitness by applying genetic algorithm during idle time of the server. By using the improved chromosome in server for the client's genetic algorithm processing, the convergence speed of the optimal solution is increased. The improvement of fitness at the server during the interval of chromosome migration is (equation omitted)(F$_{max}$(g)-F$_{max}$(g-1)), whole F$_{max}$(g) is a max fitness of the g-th generation and G is the number of improved generation by the server. As the number of clients increases and G decreases, the improvement of fitness goes down. However the improvement of fitness is better than existing methods..

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.106-111
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• 2005

For breeding of a new rootstock for eggplant production, somatic hybrids between two species, Solanum integrifolium and S. sanitwongsei were obtained through protoplast fusion. The former species has been commonly used for rootstock for eggplant production in Japan. Eggplants on these rootstocks are more productive than ungrafted plants, but are susceptible to bacterial wilt caused Ralstonia solanacearum. While the latter species is resistant, the growth of eggplants on this rootstock is rather slow and low yield. Protoplast of both species were isolated from cotyledons, and inactivated with iodoacetamide or UV-irradiation, then fused electrically. The fused products were then cultured. Regenerated plantlets were then transplanted on soil then maintained in a green house. The plants were classified into four groups. Those in the first group showed morphological characters intermediate of the parentalspecies. The plants bore fruit with viable seeds. The plants showed a chromosome number of 2n=48, the sum of those of the parental species, and are suggested to be symmetric fusion products. While plants in the other groupswas less vigorous and showed chromosome number 2n= 68 to 72 suggesting asymmetric fusion products by genomic in situ hybridization(GISH). Isozyme pattern of shikimate dehydrogenase (SKDH; EC 1.1.1.25), isocitrate dehydrogenase (IDH; EC 1.1.1.41) and phosphoglucomutase (PGM; EC 2.7.5.1) showed that 24 regenerated plants in three groups were somatic hybrids. Analysis of random amplified polymorphic DNA (RAPD) showed that 43 S. integrifolium-specific and 57 S. sanitwongsei-specific bands were all found in 24 plants. Both somatic hybrids and its S1 plants were found to be resistant to bacterial wilt, and eggplant grafted these plants using for rootstocks were more productive than grafted mother plants. Now, S1 progenies are used for commercial eggplant production in Osaka Prefecture.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.1
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• pp.1-10
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• 1997

Unreduced (2n) gametes are meiotic products (pollen or egg) having a sporophytic (somatic) chromosome number, resulting from abnormalities during either microsporogenesis or megasporogenesis. They occur naturally at a low frequency in many plant species. Unreduced (2n) gametes in plants can be identified for four possible ways as follow i) pollen size and/or shape differences between haploid (n) and diploid (2n) pollen, ii) ploidy analysis (chromosome number) of progeny or meiotic analysis (presence of dyads andlor triads at the microspore stage), iii) progeny performance and fertility and iv) dosage of isozyme and DNA markers. Unreduced (2n) gametes can be an effective breeding tool in synthesizing new cultivars, providing a unique method to maximizing heterozygosity, i.e., transferring a large proportion of the non-additive genetic effects (intra- and inter- locus interactions) h m parent to offspring and can also be used to overcome infertility of interploidy crosses. Sexual polyploidization through 2n gametes has been a major route to the formation of naturally occurring polyploids. The three mechanisms of 2n pollen formation in potato have been discovered as follow: i) parallel spindles (ps) or tripolar spindles (ts), ii) premature cytokinesis (pc-I, pc-2) and iii) synaptic mutants (sy-2, sy-3, sy-4). Genetic analysis indicated that the mechanisms of 2n gamete formation were controlled by single recessive gene in potato, alfalfa, red clover, etc., and by two recessive genes in wheat. The use of 2n gametes which can efficiently transfer germplasm fiom wild relatives to cultivated species, especially fiom diploid to tetraploid could make a contribution to the improvement of germplasm base in breeding programs.