• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.4
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• pp.455-459
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• 1985

This study is to select good diploid clones and develope them into FDR clones. Seventeen diploid clones were selected by tuber plants from the imported diploid potato seeds and from the progenies of the crosses between them. The characteristics of the selected clones were reported. Fifteen clones were crossed among them or open pollinated or bulk pollinated, and 18 selections were made from the seed progenies of these pollinations. Male and female unreduced gametes were searched by crossing 2x, 4x and by microtechnique. Only one clone, D6-21 was found to produce unreduced male gamete with the rate of 27-30% by FDR. Unreduced female gamete has not been found among these diploids.

• Journal of Sericultural and Entomological Science
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• v.44 no.1
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• pp.13-18
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• 2002

The morphorogical characteristics of the Morus tiliaefolia growing wild in the Korean peninsula are as follows. The chromosome number of somatic cell is 2n=84,that is hexaploid. The shape of male inflorescence is a long cylinder shape of 3.6∼6.0 cm. The length of female inflorescence is 1.8 cm, red violet or violet and the weight of mulberry fruits is 1.39∼1.65 g. The winter bud is very big in comparison with the branch and the accessory bud does not exist. The leaf is big and lobed leaf or entire leaf, the density of lenticell is 9.42$\pm$1.29 ㎠. The length of leaf trichome is 236∼438 ㎛ and the distribution density is 16∼37/25 ㎟ and heigh density of leaf back. The trichome shape of the leaf surface is cylinder shaped, in the leaf back it is thin and long corn shaped.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.1
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• pp.104-111
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• 1997

Since seeds of Italian ryegrass should be imported every year, it is necessary to investigate the prossible production of seeds in Italian ryegrass field after rice. Seven Italian ryegrass varieties were planted on October 8, 1986 at National Honam Crop Experiment Station at Iksan and clippings were made on April 10 and April 30 in 1987. Headings of K-11 and T.N.T were earlier than those of Tetrone and Bettina. For all varieties tested, heading date was delayed and 1,000 grain weight was decreased linearly as the clipping was made later. Length, width and thickness of a grain were reduced by clipping and later clipping, while tetraploid varieties produced larger grains than diploid varieties. The germination percentage and germination speed at $25^{\circ}C$ were higher than at 15$^{\circ}C$. The final germination percentage was lower at the later clippings and was higher at 15$^{\circ}C$, and earlier varieties showed higher germination percentage. Uniformity of germination was greater at $25^{\circ}C$ and was decreased as the clipping was made later, and the eariler varieties such as K-11 were germinated more uniformly. Average number of days to germination was longer at 15$^{\circ}C$ than at $25^{\circ}C$ and was longer at later clipping. The germination percentage was decreased linearly as the heading was delayed, while it increased linearly as the 1,000 grain weight was increased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.413-419
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• 1995

This study was conducted to find out the suitable NaCl concentration and temperature for investigating the varietal difference of salinity tolerance in Italian ryegrass. Seeds of 20 cultivars including 9 diploid and 11 tetraploid were exposed to eight levels of NaCl concentration ranging from 0 to 350mM under three temperature levels of 15, 20 and $25^{\circ}C$. The NaCl concentration(C50%) inhibited germination of 50% of the viable seeds for the cultivars at 15$^{\circ}C$ was 354mM, and those at 2$0^{\circ}C$ and $25^{\circ}C$ were 342mM and 325mM, respectively. There were significant correlations among C50% at three levels of temperature, and correlation coefficient for C50% between 2$0^{\circ}C$ and 15$^{\circ}C$ was higher than that between $25^{\circ}C$ and 15$^{\circ}C$ or 2$0^{\circ}C$. C50% was positively correlated only with germination speed at 10 days after sowing when the plants were exposed to 350mM NaCl at 2$0^{\circ}C$. For the germination speed at 10 days after sowing in 350mM NaCl at 2$0^{\circ}C$, the cultivars used could be classified into three groups. Wase Aoba, Bettina, E. K -11, Tetrone, Lira Sand, Tetra Florum and Billiken belonged to the tolerant group, and Tuchi Was, Wase Yutaka, Sakura Wase, Magnolia, Limella and Delita were as the semi-susceptible group, and Atalja, Barmultra, Ajax, Liberta, LM-16, Elving and Wilo were as the susceptible group.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.1
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• pp.19-26
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• 1970

During the summer of 1969, a series of experiments on the spawning and development of the eggs of grass carp and silver carp was performed with the following results, but the complete development of eggs Iras not accomplished: 1. The season of maturity for both species is estimated to be from the end of June to the beginning of August. 2. Pituitary glands for the use of inducing maturation should be obtained before the maturation season of its donor. 3. Silver carp as small as 40 cm in body length (48 cm in total length) with an age of 6 years were found to have reached maturity, and the number of eggs in the ovaries were from about 23 to 26 thousand for those with body lengths of 40-44.5 cm. 4. The conical-shaped net cloth incubator worked better than others, and each incubator was most effective when installed in parallel series to the water supply pipe with a valve for each incubator to control water flow. 5. During the egg development, if any cell or cells were displaced, the eggs eventually died. 6. The proper manipulation of brood fish before the egg-taking seems to be very Important, and close care should be paid to feeding them well and keeping them in a pond of proper water depth.

• Korean Journal of Ichthyology
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• v.8 no.2
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• pp.10-15
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• 1996

The chromosome numbers of bagrid catfish, Pseudobagrus fulvidraco was 52, nine pairs (No. 1 to 9) were metacentrics with the range of relative length 2.89~6.22 and arm ratio 1.09~1.58 ; thirteen pairs (No. 10 to 22) were submetacentrics with the range of relative length 2.88~5.88 and arm ratio 1.80~3.65 ; and all other pairs (No. 23 to 26) were acrocentrics with the range of relative length 2.63~3.30 and arm ratio 9.01~10.67, and fundamental number was 104. Heteromorphic sex chromosomes were not found. There was not exist significant difference in resultant erythrocyte measurements and parameters between female and male (p<0.05). The mean sizes of cell and nucleus, were $11.03{\times}9.67{\mu}m$ and $4.18{\times}3.66{\mu}m$ respectively. The number of erythrocytes of both females and males were $6{\sim}7{\times}10^5/ml$. Gill tissues from diploid individuals had cells with one or two nucleoli.

• Korean Journal of Plant Tissue Culture
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• v.24 no.2
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• pp.113-117
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• 1997

Simple sequence repeats (SSR) are widely dispersed throughout eukaryotic genomes, highly polymorphic, and easily typed using polymerase chain reaction (PCR). The objective of this study was to determine the polymorphism of different Chlamydomonas reinhartdtii strains and to determine the mode of inheritance of the SSR locus in Chlamydomonas. A genomic DNA library of C. reinhardtii was constructed and screened with a radiolabeled $(AC)_{11}$ probe for the selection of (CA/GT)n repeat clone. Selected clone was seqeuenced, and PCR primer set flanking (CA/GT)n sequence was constructed. PCR was used to specifically amplify the SSR locus from multiple isolates of C. reinhardtii. The locus was polymorphic in some of the C. reinhardtii isolates. However, the locus was amplified only 4 of 6 isolates of C. reinhardtii, not in other 2 isolates of C. reinhardtii, suggesting that this locus is not extensively conserved. A simple Mendelian inheritance pattern was found, which showed 2:2 segregation in the tetrads resulting from a cross between C. reinhardtii and C. smithii. Our results suggest that this simple sequence repeat DNA polymorphism will be useful for identity testing, population studies, linkage analysis, and genome mapping in Chlamydomonas.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.6
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• pp.452-457
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• 2008

This study analyzed the proximate compositions, total amino acids, and fatty acid compositions in muscle and viscera of 51-month-old triploid and diploid Pacific abalone, Haliotis discus hannai. Proximate composition analysis showed that the muscle of diploid abalones had a higher protein and ash ratio than that of triploid abalones, while there was no significant difference in the ratios of moisture and fat (P>0.05). The triploid abalones had a significantly higher ratio of carbohydrate in muscle than the diploid abalones (P<0.05), which suggests that the transference of carbohydrates from muscle to gonad is decreased in sterile triploid organisms. Amino-acid analysis indicated that the total content was 133.42 mg/g in diploid muscle and 151.46 mg/g in triploid muscle. Taurine, arginine, glutamine, glycine, glutamic acid, alanine, and leucine, which are the major amino acids in abalone, were measured as 84.64 mg/g in triploid muscle and as 73.92 mg/g in diploid muscle. The essential amino acid content of triploid muscle (38.83 mg/g) was significantly higher than that of diploid muscle (31.94 mg/g) (P<0.05). Saturated fatty acids and monoene fatty acids were abundant in triploid muscle and polyene fatty acids were abundant in diploid muscle. Therefore, triploid Pacific abalone appears to be a good nutritional food source.

• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.325-330
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• 1991

In order to develop yeast strains which can effectively produce ethanol from cellulosic hydrolyzates, protoplast fusion between Candida sp. KM-09-135 and Saccharomyces cweoisiue SM-07 was carried out and obtained the excellent fusant KMS-23. Fusant KMS-23 showed the optimal growth temperature and ethanol productivity at $37^{\circ}C$, and assimilated xylose, cellobiose, maltose and raffinose as fermentative sugars. Cell size of the fusant was about 1.2 times greater than that of KM-09-135 and 1.5 times SM-07. DNA content of fusant was 1.3 times higher than that of SM-07 and similar with KM-09-135. Fusant KMS-23 produced 2.57% (v/v) ethanol from saccharified wheat bran containing 6.44% (w/v) of reducing sugar, which was 1.3 times higher than parent strains under the same conditions.

• Korean Journal of Plant Taxonomy
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• v.34 no.2
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• pp.153-166
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• 2004

Genus Taraxacum propagated through diploid sexual reproduction and polyploid agamospermy. The cluster analysis of Korean(2 species, 4 population), Japanese (2 species 4 taxa 6 population) and Taiwanese (1 species, 3 population) Taraxacum species using 15 measured capitulum morphological characters was conducted to study the speciation of diploid Taraxacum in East Asia. We measured 15 capitulum morphological characters including length of capitulum, length and shape of outer-involucre, corniculate appandage. Within one population, these characters were very various and were overlapped. The result of cluster analysis using morphological character showed that all species were clustered into four groups (Korean species & T. japonicum group, T. platycarpum subspecies group, T. platycarpum subsp. hodense group, T. formosanum group). Korean species, T. hallaisanense (diploid) and T. ohiwanum (diploid, triploid) were clustered into T. japonicum that was occurred in Kansai provinces of Japan. Therefore, we could infer that Korean species was closely related to Japanese T. japonicum of Japanese species.