• Korean Journal of Poultry Science
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• v.15 no.2
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• pp.67-71
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• 1988

In order to induce the diploid gamete(ovum) under suppression of meiosis in oogenesis for production of polyploid chicken. this experiment checked meiosis time. through regular ovulation and response of inhibitor (Tri-ethylen Melamine) to meiosis. The results obtained was follows; ＊Meiosis of oogenesis was 2-4 hours before ovulation. ＊Response of inhibitor to meiosis was effective at 0.3mg triethylen melamine per kg body weight. ＊Fertility was highly decreased by influence from inhibitor. ＊66% of fertilized eggs was triploid(3n) through fertilization induced diploid ovum (2n) with normal sperm(n).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.3
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• pp.298-301
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• 2019

We investigated the development of allotriploid embryos derived from a cross between female starry flounder Platichthys stellatus and male stone flounder Kareius bicoloratus. The second cleavage, mid-blastula, gastrula, and Kupffer's vesicle appearance stages, and hatching of embryos began 3.7, 25.6, 45.7, 87.7, and 213.2 h after cold shock at $6^{\circ}C$, respectively. The hatching and development time of triploid interspecific hybrid eggs was approximately the same as those of diploid starry flounder eggs at the same incubation temperature.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.481-491
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• 2009

This study was conducted to observe some characteristics of aneuploid trees obtained from the crosses between diploid and triploid in the first experiment. The results showed that the difference among the percentage of aneuploid's pollen grain germination was large, and all of them were lower than that of diploid 'Hongro' (82.4%). The average weight and size of each aneuploid's fruit was far lighter and smaller than that of diploid 'Hongro'. According to the width and length, all of the fruits shape was flat or short-globose conical shape except for JF3942. Almost all the aneuploid had higher sugar content than 'Hongro', nearly half of aneuploid fruits were firmer than that of diploid 'Hongro'. As for the acid contents of aneuploid fruits, the results were greatly different from those of previous studies on diploid apples, in present study the citric acid and tartaric acid contents were more than the malic acid which are dominant acid in most cultivars of apples. Both the length and width of aneuploid tree were shorter than that of diploid 'Hongro'. Most aneuploid trees' height was longer than width, but there were 4 exceptions. The size of leaves was smaller than that of diploid 'Hongro' according to the length and width of leaves measured. In all, aneuploid's vegetative growth is not as vigorous as diploid.

• Korean Journal of Plant Tissue Culture
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• v.21 no.4
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• pp.239-246
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• 1994

The genotypic (2n, 3n, 4n) response of watermelon in vitro shoot tip culture was evaluated. Different genotypes had similar response in terms of shoot formation and growth. Shoot formation was better at lower concentration of 0.3 mg/L BA and higher concentration of 5-10.0 mg/L 2iP and kinetin, but growth of newly formed shoot was inhibited. With further subculture, kinetin did not promote shoot formation Better shoot formation was observed at 0.3-0.5 mg/L BA. Combination of 0.3 mg/L BA and 0.3-0.5 mg/L BA was effective in shoot multiplication, growth and induction of more internodes. Varrying levels of light intensity and agar concentration did not affect the performance of tetraploid plants. Higher light intensity and agar concentrations decreased the number of shoot formed in triploid plane. Growth in both genotype, however was inhibited. Higher light intensity was found to promote leaf senescence in all genotypes. All growth inhibitors decreased the number of shoots formed and slowed plant growth there by prolonging duration of cultures. Growth inhibitors were to observed to decrease incidence of hyperhydricity in culture. No difference in shoot formation was observed in each of the concentrations used in Ancymidol, TIBA, CCC and PP333. Shoot formation and growth was more inhibited in ABA treatments. Leaf expansion and growth was poor in all treatments.

• Development and Reproduction
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• v.13 no.2
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• pp.115-122
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• 2009

Spermatogenesis and ultrastructural characteristics of sperm of brackish water diploid Corbicula japonica were investigated by electron microscope observations. Based on the cytological studies, the spermatozoon of this species (brackish water diploid) C japonica is approximately 55 ${\mu}m$ in length. The sperm head (about 12 ${\mu}m$ long) is elongated and tapers with a slight curve. Sperm nucleus is about 7.90 ${\mu}m$ long, and the acrosome is about 2.70 ${\mu}m$ long: The morphologies of the sperm nucleus type and the acrosome shape of this species are a long arrow-like type and long cone-like shape, respectively. The sperm head of this species (external fertilization, dioecious and oviparous species) is partially modified from that of the primitive type, as seen in triploid Corbicula species (internal fertilization, hermaphrodite and ovoviparous species), reported by some authors. However, this species produces uniflagellate spermatozoa, unlike freshwater triploid hermaphroditic clams being possessed of partially modified biflagellate spermatozoa. Diploid C japonica is similar to those of other bivalves being possessed of a short midpiece containing four mitochondria surrounding the centrioles. The axoneme of the sperm tail flagellum consists of nine pairs of microtubules at the periphery and a pair at the center. The axoneme of the sperm tail shows a 9+2 structure, and from uniflagellate sperm cross sectioned, in particular, wing-like axonernal lateral fins are observed, as seen in external fertilization fishes.

• 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.

• Journal of Sericultural and Entomological Science
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• v.43 no.1
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• pp.9-15
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• 2001

New Mulberry Cultivar, Milsungppong, was selected from F1 seedlings obtained by crossing the female, 4X Keomseolppong, and the male, Kaeryangppong. Local adaptability test has been carried out at five places(Suwon, Chunchun, Cheongju, Kongju and Sangju) for four years since 1992. Leaf quality was tested by silkworm rearing for two silkworm rearing seasons(spring and autumn) at Suwon in 1995. From these tests, Milsungppong was found to be superior to control cultivar, cultivar, Kaeryangppong, in productivity, rootability and shoot cold injury. The new cultivar, Milsungppong, has following agronomic characteristics as compared with Kaeryangppong, the most prevailing cultivar, Milsungppong, has following agronomic characteristics as compared with Kaeryangppong, the most prevailing cultivar in Korea It is triploid cultivar belonging to Morus bombycis KOIDZ with the leaf shape of five lobes, sprouting in spring nearly the same to the Kaeryangppong (Morus alba L.), high leaf yielding of 25% compared to Kaeryangppong (Morus alba L.) and the medium degree of cold resistance. It is adaptable to every where in Korea except the area cold injury broken out habitually. Milsungppong is recommended to rear silkworms not only in spring but also in autumn besides for young silkworms.

• Journal of Sericultural and Entomological Science
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• v.36 no.1
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• pp.1-7
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• 1994

Four tetraploid mulberry lines, Sawonppon No.11, No.13 and No.14, were induced by the colchicine treatment on the shoot tips of seedlings originated from the cross between Yongchonppong and Kaeryanppong. The major characteristics of the tetraploid lines were as follows: Green tip sprouting stage was similar to Kaeryanppong, a medium budding variety. Leaves were medium- to large-sized cordate type. Leaf surface was rougher and stronger than that of the diploid parents. Leaf thickness, leaf area weight and leaf water content were higher than those of the diploid parents. Average branch length was shorter than that of the diploid parents. Internode length and number of lateral branches were similar to the average values of the two parents. Death atop rate of branch was 1.6%~2.5% indicating strong cold-hardiness of the tetraploid lines. Therefore, these lines could be used as sources of cold-hardiness in developing triploid lines.

• Korean Journal of Microbiology
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• v.29 no.1
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• pp.8-15
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• 1991

Interspecific hybrids between the ASpergillus spp., A. awamori, A. usamii and A. oryzae, were obtained by nuclear transfer technique. Nuclei isolated from an auxotrophic mutant strain were transferred into the protoplasts of a recipient strain of different species. The frequency of interspecific hybrid formation by nuclear transfer was $2*10^{-5}$ $-7*10^{-4}$ In contrast, no interspecific hybrid was isolated by protoplast fusion. Among the hybrids tested, 10 strains showed increased activity of some or all components of cellulases, xylanases and amylase up to more than two times. Isozyme pattern of the hybrids were analyzed by polyacrylamide gel electrophoresis and isoelectric focusing followed by activity staining, which showed that some of the hybrids have isozyme patterns unidentical to either of the two parents. By measuring the DNA contents and the sizes ofthe conidia, the karyotypes of the hybrids were estimated to be aneuploid near to haploid, diploid or triploid. It was concluded that the unclear transfer technique is much more efficient in the formation of interspecific hybrids than protoplast fusion and is very useful for the improvement of Aspergillus strains.

• Journal of Korean Society of Forest Science
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• v.71 no.1
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• pp.22-26
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• 1985

Cytological observations in the seven varieties of Juniperus chinensis L. showed three varieties (J. chinensis var. procumbens, J. chinensis var. kaizuka and J. chinensi.s var. aureo-variegata) were tetraploid with chromosome number, 2n=44, and rest of four varieties (J. chinensis var. horizontalis, J. chinensis var. sargentii, J. chinensis var. gtobosa and J. chinensis var. aureo-globosa) to be diploid, 2n=22. Chromosome configuration and behavior in the meiosis of P.M.C. of three tetraploids appeared to be slightly irregular. These results suggest that triploid tree can be artificially produced with these specific clones.