• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.903-909
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• 2022

Triploid fish have attracted the attention of fish farmers owing to of their larger cell size compared to that of diploid fish and their ability to utilize the energy required for sexual maturation for growth instead. However, the effect of increased growth in triploid fish has shown varying results. Therefore, this study aimed to compare growth between diploid and triploid starry flounders and diploid and triploid hybrid juveniles (starry flounder, Platichthys stellatus ♀×stone flounder, Kareius bicoloratus ♂) based on breeding water temperature to investigate the effect of increased growth in triploid fishes. The experiment was performed by categorizing the water temperature as high temperature (EXP. 1, 14.5-23.5℃) and low temperature (EXP. 2, 6.4-13.3℃) based on the optimal water temperature for starry flounder breeding. In EXP. 1, the growth of starry flounder triploids and hybrid triploids was significantly higher than that of diploids. However, in EXP. 2 the weight gain and specific growth rate of the starry flounder triploid were higher, and the growth of starry flounder was higher than that of the hybrids.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.1
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• pp.10-14
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• 2013

This experiment was carried out to breed an early maturing variety of Italian ryegrass (Lolium multiflorum Lam.) in the Grassland and Forage Crops Division, National Institute of Animal Science, RDA, Cheonan from 2009 to 2011. A new variety, 'Green farm II' is a diploid with green leaves and has a semi-erect growth habit in late autumn and erect growth habit in early spring, respectively. 'Green farm II' was on the $28^{th}$ of April in the heading date as an early-maturing variety. 'Green farm II' was also wider by 0.6 mm in flag leaf width, shorter by 1 cm in flag leaf length and shorter by 1 cm in plant length than those of the control variety, 'Florida 80', respectively. 'Green farm II' was thicker by 0.7 mm in stem thickness and strong in winter hardness. Dry matter (DM) yield (11,452 kg/ha) of 'Green farm II' was similar to that of 'Florida 80'. In vitro dry matter digestibility (IVDMD), total digestible nutrients (TDN), and relative feed value (RFV) of 'Green farm II' were 70.6%, 63.9%, and 114% higher than those of 'Florida 80', respectively. Acid detergent fiber (ADF) and neutral detergent fiber (NDF) of 'Green farm II' were 31.7% and 52.6% which were 3.5% and 6.4% lower than those of 'Florida 80', respectively.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.618-626
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• 2010

Matroclinal inheritance of morphological characters in interspecific crosses of Rosa spp. can be influenced by cytoplasmic inheritance, apomixis, and asynaptic heterogamy. In asynaptic heterogamy, which is often observed from interspecific crosses of Rosa sect. $Caninae$, the polyploidy of the seed parent (especially for 5x=35) is recovered in the progeny through the pollens that include only a set of bivalents (x=7) and egg cells that contain a set of bivalents (x=7) and other univalents (3x=21). In this study, we investigated the causes of matroclinal offsprings observed from reciprocal crosses of tetraploid cut rose cultivars ($Rosa$ $hybrida$ L.) by analyzing EST-SSR marker distribution in the progeny populations. From EST-SSR marker analysis of eight offsprings per six reciprocal crosses among six cultivars, cases of cytoplasmic inheritance were not observed. Apomixis was also very rare as compared to the reports on interspecific crosses of sect. $Caninae$; only one apomitic plant was identified from the cross 'Redtem' ${\times}$ 'Red Sandra'. Although a clear-cut pattern of asynaptic heterogamy was not found, cultivar-specific marker transmission skewed to seed parent in four cultivars implied that genetic inheritance can be highly influenced by the seed parent depending on crosses among cut rose cultivars; especially, 10 out of 11 alleles specific to 'Yellow King' distributed in progenies at higher ratios when the cultivars were crossed as the seed parent.

• Korean Journal of Ichthyology
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• v.34 no.2
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• pp.86-95
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• 2022

Egg development and morphological change of larvae and juvenile of the Roughscale sole, Clidoderma asperrimum, were investigated in the present study. Adult fishes were collected on the East Sea, Korea, from 2017 to 2018 and reared in a circular water tank (Ø 6×1 m) at water temperature of 12.8±1.9℃. Fertilized eggs ranged from 1.42 to 1.59 mm (mean 1.51±0.04 mm, n=50) in diameter. The eggs were spherical in shape, transparent, floating and colorless. The egg yolk was separated from the egg membrane 60 mins post-fertilization (PF), and an embryo was formed in 62 hrs PF. More than 50% of the eggs hatched within 144 hrs PF in the range of 10.2~11℃(mean 10.8℃). The size of the newly hatched larvae were 4.22~4.64 mm (mean 4.53±0.16 mm) in total length (TL), their mouth and anus were not open yet. At 10 days after hatching, the preflexion larvae reached 5.88~6.62 mm (mean 6.31±0.33 mm) in TL, and the yolk absorption was completed and the mouth began to open. At 55 days after hatching the larvae reached to flexion larvae stage and they were 10.4~13.3 mm (mean 12.7±1.3 mm) in TL, and the tip of notochord was bent upward. At 120 days after hatching the larvae reached to juvenile stage and they were 35.3~40.5 mm (mean 39.5±2.4 mm) in TL. Their all fins had completed set of the fin-rays (D. 79~94: A. 63~75) and the juveniles adopted a benthic life.

• Korean Journal of Ichthyology
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• v.21 no.4
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• pp.247-252
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• 2009

The egg development and early life history of the Korean endangered fish Koreocobitis naktongensis (Cobitidae) were investigated. Eggs from the females were obtained by injecting 10 IU/g of human chorionic gonadotropin and inseminated with sperm by the dry method in the laboratory. The fertilized eggs were 1.0~1.2 mm in diameter and had no oil globules. The embryo began to hatch about 38 hrs after fertilization under water temperature of $20{\pm}1^{\circ}C$. The newly-hatched larvae were 2.6~2.8 mm in total length, and their mouth and anus were not yet opened. Seven days after hatching, the postlarvae were 4.5~5.2 mm in total length, and their yolk sacs were completely absorbed. They entered the juvenile stage when all fin-rays were formed at 50 days after hatching, and their total lengths were 21~27 mm.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.6
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• pp.316-325
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• 2006

In diploid organisms like human, each chromosome consists of two copies. A haplotype is a SNP(single nucleotide polymorphism) sequence information from each copy. Finding the complete map of haplotypes in human population is one of the important issues in human genome. To obtain haplotypes via experimental methods is both time-consuming and expensive. Therefore, inference methods have been used to infer haplotyes from the genotype samples. In this paper, we propose a new approach using genetic algorithm to infer haplotypes, which is based on the model of finding the minimum number of haplotypes that explain the genotype samples. We show that by doing a computational experiment, our algorithm has the correctness similar to HAPAR[1] which is known to produce good results while the execution time of our algorithm is less than that of HAPAR as the input size is increased. The experimental result is also compared with the result by the recent method PTG[2].

• Horticultural Science & Technology
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• v.29 no.5
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• pp.507-509
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• 2011

'Heukisul' (3x) a cross made in 2000 between 'Kyoho' (4x, Vitis sp.) and 'Thompson Seedless' (2x, Vitis vinifera L.) in a seedless grape breeding program, was preliminarily selected in 2004. After regional adaptation testing under the name of 'KTS014' at two sites during 2004-2005, it was finally selected in 2006. 'Heukisul' showed low incidence of berry shattering, resulting in a good berry set compared to 'King Dela'. 'Heukisul' had budburst on April 23, flowering on in June 9, and fruit maturation in September 29 (almost the same as 'King Dela' at Chuncheon), and it was considered a midseason cultivar. The mean berry weight was 4.0 g, about 0.7 g heavier than 'King Dela', and mean soluble solids were $21.9\;^{\circ}Brix$, about $2.7\;^{\circ}Brix$ higher than 'King Dela'. The skin color was dark violet with abundant bloom and the flesh was very firm. Although the cluster was compact, it required no cluster thinning. Also the incidence of berry cracking was very low.

• Korean Journal of Plant Taxonomy
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• v.41 no.1
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• pp.51-57
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• 2011

The microstructure of the leaf epidermis and trichomes of Fallopia sect. Reynoutria are examined using scanning electron microscopy. Fallopia sachalinensis was distinguished from other taxa in this section by its prominent epicuticular wax layer consisting of protruding wax rodlets. In addition, epicuticular rodlets of F. sachalinensis individuals from Ullung Island and Dok Island appear to be thinner than those from other regions, including Japan and Sakhalin. The stomatal size appears to be related to the ploidy level in the sect. Reynoutria, as the hexaploids, octoploids and dodecaploids tend to have larger stomata as compared to tetraploids. Three basic types of trichomes were found in the section; (1) conical unicellular trichomes, (2) uniseriate filiform trichome consisting of 1-8 cells, and (3) peltate glandular trichomes. The trichome types and their distribution appear to be useful in distinguishing the taxa in the section.

• Korean Journal of Plant Tissue Culture
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• v.26 no.1
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• pp.1-6
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• 1999

In order to obtain plantlet derived by anthers, the anthers of Lilium asiatic hybrid 'Gran Paradiso' were cultured on Murashige and Skoog's medium supplemented with various combinations of auxin and cytokinin. The most suitable pollen stage of anther culture for the callus induction was 3 days before anthesis at the early to late binucleate stage. Organogenic calli were induced on MS medium supplemented with 5.0 mg/L 2,4-D alone and the combination of 1.0 mg/L 2,4-D and 1.0 mg/L kinetin, however, the combination of NAA and BA was more effective than that of 2,4-D and kinetin on plant regeneration through organogenesis. Shoots were formed from the induced callus on the medium with 0.5 mg/L NAA and 1.0 mg/L BA after 180 days of culture. Multiple shoots with 3-4 leaves, roots, and bulblets were formed on the medium with the combination of 2.0 mg/L NAA and 2.0 mg/L BA after 250 days of culture. The chromosome from root tip of the regenerated plantlet showed the diploid (2n=2x=24). Diploid plants were transferred to the pots and all plants were flowered in two years.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.853-859
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• 2014

The goal of this study was to evaluate the effects of cryoprotectants [dimethyl sulfoxide (DMSO), methanol, polyethylene glycol, and propylene glycol], cryoprotectant concentrations (10% and 20%), equilibration time (3, 10, and 30 min), cooling rate ($3^{\circ}$, $5^{\circ}$, $7^{\circ}$, and $10^{\circ}/min$), and straw size (0.25 and 0.5 mL) for sperm cryopreservation of tetraploid Pacific oysters. There was a significant difference among the four cryoprotectants, with 10% DMSO yielding the highest post-thaw survival and activity index of sperm. A significant relationship was observed between the cryoprotectant and its concentration. The sperm with equilibration times of 30 min yielded higher post-thaw survival and activity indices than those with 3 and 10 min equilibration times. The sperm cooled at a rate of $5^{\circ}/min$ yielded the highest post-thaw survival and activity index, and the results were significantly different from those observed for cooling at $7^{\circ}$ and $10^{\circ}/min$. Post-thaw survival and activity indices of sperm using a 0.25-mL straw were significantly higher than those using a 0.5-mL straw.