• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.735-740
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• 2019

The aim of this study was to conduct a comparative analysis of the diploid and induced triploid cell cycles in marine medaka, Oryzias dancena, tissues. The mean fraction of cells in the G₁, S, and G₂+M phases was 85.5%, 7.6%, and 6.9%, respectively, in the tail fin tissues of diploid fish and 91.2%, 3.6%, and 5.2%, respectively, in those of induced triploid fish. The mean fraction of cells in the G₁, S, and G₂+M phases were 78.4%, 10.6%, and 11.0%, respectively, in the liver tissues of diploid fish; 86.2%, 5.9%, and 7.9%, respectively, in those of induced triploid; 79.3%, 9.4%, and 11.3%, respectively, in the gill tissues of diploid fish; and 85.7%, 5.4%, and 8.9%, respectively, in the induced triploid fish. The differences among the tissues were statistically significant within both the diploid and induced triploid fish (p<0.05). Mitosis was more active in each tissue of the diploid fish than in the corresponding tissues of the induced triploid fish and mitosis was more active in the liver and gill tissues than in the tail fin tissues in both the diploid and induced triploid marine medaka.

• Journal of Aquaculture
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• v.7 no.1
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• pp.55-61
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• 1994

Triploid fish were induced successfully in olive flounder (Paralichthys olivaceus) by cold shocking fertilized eggs 3 minutes post fertilization at $2^{\circ}C$ for 45 minutes. Percent incidence of triploid was $92.6\%$ in this treatment. Floating rate and fertilization rate of eggs were not significanlty different from that of diploid controls (P> 0.05). However, hatchability and abnormal larvae of triploids were significantly different from that of diploid controls (P< 0.05). Incidence of triploidy was confirmed by erythrocyte measurements and chromosome counts. The surface area of triploid erythrocytes and nucleus was 1.6 times larger than that of diploids. Diploids had 48 acrocentric chromosomes, while triploids had 72.

• Journal of Aquaculture
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• v.6 no.1
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• pp.55-62
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• 1993

A tetraploid cyprinid loach, Misgurnus anguillicaudatus was induced by applying heat shock. The efficiency of inductions changed with the time of initiation of treatment and the duration of treatment. The highest incidence of tetraploid was obtained at the treatment of $41^{\circ}C$ for 3 min, 28 min after fertilization. Ploidy level was estimated by kariological examination and flow cytometric analysis. The tetraploid cyprinid loach had 4n = 100 chromosomes, while the diploid had 2n = 50. The erythrocytic volume of the tetraploid was 1.65 times larger than that of the diploid. The DNA content of the tetraploid and diploid showed 6.547 pg/cell and 3.067 pg/cell, respectively.

• Korean Journal of Ichthyology
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• v.6 no.1
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• pp.71-78
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• 1994

Fertilized eggs of red seabream, Pagrus major were subjected to cold shock with various initial treatment times and durations. Cold shocks at $3^{\circ}C$ for 20 minutes and 30 minutes at 6 minutes after fertilization yielded the highest triploid incidence with 100%. Triploidy was confirmed by erythrocyte measurements and chromosome counts. Diploid ad 48 acrocentric chromosomes. while triploid had 72 acrocentrics. Triploids revealed increased erythrocyte size compared to their diploids and early growth rates of triploids from 10 days to 34 days after hatching were slightly lower than that of their controls.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.589-594
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• 2002

Natural clonal stock of triploid crucian carp, Carassius aurahs was identified and its cytogenetic, molecular genetic and morphological traits were studied. Cytogenetic analysis of the clonal crucian carp revealed that they were natural triploidy, evidenced by 1.5-fold increases of cell size, DNA content, and chromosome number. Multi-locus DNA fingerprinting using $(GATA)_4$ probe showed that they had an identical fingerprint profile, indicating the clonal propagation of the population. External morphology and morphometric characteristics of triploid individuals were much uniform compared to those of diploids. Natural triploid crucian carp was proven to be all-female in this study.

• Korean Journal of Plant Tissue Culture
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• v.24 no.3
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• pp.175-181
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• 1997

Plants were regenerated from hypocotyl protoplast culture of cabbage (F$_1$hybrid Green Challenger) and were transplanted on fields. The ploidy level of regenerated and seed-grown plants was measured by flow cytometry. In total 125 regenerated plant, diploid (2n), tetraploid(4n), and mixoploid (2n+4n) were 72.8%, 25.6%, and 1.6%, respectively. Most of the regenerated plants had normal phenotype, whereas several plane showed abnormal phenotype such as heavy leaf incision, savoy, and wave. The regenerated plants with abnormal phenotype and different ploidy level were analysed by isozyme and RAPD, but no significant difference was found.

• Korean Journal of Ichthyology
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• v.6 no.2
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• pp.206-221
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• 1994

Morphometrical data for diploid and induced triploid cherry salmon, Oncorhynchus masou were analyzed prior to the spawning season to compare their commercial values. The following traits were measured with the diploids and induced triploids : ungutted and gutted body weight; body length; dressing percentage; condition factor; gonad weight and gonad index; belly thickness; viscera weight; viscera index; body circumference at the pelvic, dorsal and anal fins; area of the cross sections at the pelvic and dorsal fins; two belly thickness traits measured on each cross section; total height, height and width of each cross section; three body shape traits; and nine cross section shape traits. Body length and body weight of diploids were larger than those of induced triploids and dressing percentage, gonad weight, gonad index, viscera index, and liver index were also larger in diploids. However, induced triploids showed higher values in one belly thickness trait and some section shapes than diploids. Differences in body traits were due to the sterility of induced triploids. Therefore, induced triploid cherry salmon appears to have greater potentials for the commercial values than their diploids.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.3
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• pp.243-246
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• 1982

A proposal of gene transfer scheme from diploid to hexaploid in oats was described. The main idea of this scheme are (1) use Avena magna which has two genomes partially in common with two genomes of the hexaploid Avena sativa or a common genome and the rest genomes partially commonn, and which lead to more regular pairing between them rather than AABB genome type to get 6x-amphiploid as a bridge between ploidy level. Cross between Avena strigosa and Avena magna is compatible and further give 42% seed set, (2) extract tetraploid derivatives which have in corporated desired genes from Avena strigasa to Avena magna, (3) Synthetic petaploid provide 2n=21 chromosome number in female gametes, which lead to complete pairing or nearly so in progenies with Avena sativa, (4) eventually homozygous lines will be produced by selfing the heterozygous (regarding to$A^{As}$ genome) at final step.

• Journal of Aquaculture
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• v.9 no.2
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• pp.133-140
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• 1996

Hybird and allotriploid between female rainbow trout (Oncorhynchus mykiss) and male coho salmon (O. kisutch) were produced by artificial fertilization and heat shocks. Hatching and survival rate of allotriploid at 2 month after hatching was $77.6\%$ and $54.5\%$ respectively, and these rates clearly exceeded those of their hybrid. Cell and nuclear sizes of the erythrocyte of hybrid were intermidiate of their parents and those of allotriploid were larger than thier hybird. The somatic chromosome number of viable hybrid was 2n = 60 and that of allotriploid was $90\~93$ with chromosomal polymorphism. Allotriploid karyotpe was constituted by two sets of rainbow trout chromosome and one set of coho salmon chromosome.

• Asian Journal of Turfgrass Science
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• v.25 no.1
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• pp.17-21
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• 2011

Korean bennudagrass collections showed diverse genetic variations in their morphology, growth habit, and cytological aspects. Chromosome number and nuclear DNA content of the bennudagrasses indicated a ploidy level ranging from triploid (2n=3x) to hexaploid (2n=6x). In this study, we investigated the different responses of antioxidant enzymes (superoxide dismutase, catalase, peroxidase, ascorbate peroxidase) and cell membrane stability of those bennudagrass cytotypes to lower temperature and shorter day length, which meets a dormant induction in Korea. All the antioxidant enzymes were found to be higher during dormant stage, while the heme-containing catalase which converts hydrogen peroxide ($H_2O_2$) to water and oxygen molecules was activated before dormant initiation in the three cytotypes except for hexaploid bennudagrass. The triploid and tetraploid which exhibited relatively finer leaves and a rapid establishment speed were found to show increased activities of superoxide dismutase and peroxidase enzyme. The malondialdehyde(MDA) which is a product of lipid peroxidation in the cell membrane damaged by the hydroxyl radical was increased in all cytotypes as temperature declined, and tri- and tetraploids which had more protective antioxidant enzymes demonstrated a significantly lower MDA production. Similarly electrolyte leakage was higher in penta- and hexaploidy, seemingly more damage to cell membrane when low temperature was implemented. Results indicated that antioxidant responses of different cytotypes were genetically specific, which needs to be investigated the relevance with the low temperature tolerance in the bermudagrass further at the molecular level.