• Journal of Korean Society of Forest Science
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• v.112 no.1
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• pp.40-56
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• 2023

Tree species within the Populus genus grow rapidly and have an excellent capacity to absorb carbon, conferring substantial ability to effective purify the environment. Poplar breeding can be achieved rapidly and efficiently if a genetic linkage map is constructed and quantitative trait loci (QTLs) are identified. Here, a high-density genetic linkage map was constructed for the control pollinated progeny using the genotyping-by-sequencing (GBS) technique, which is a next-generation sequencing method. A search was also performed for the genes associated with quantitative traits located in the genetic linkage map by examining the variables of height and diameter at root collar, and resilience to insect damage. The height and diameter at root collar were measured directly, while the ability to recover from insect damage was scored in a 4-year-old breeding population of aspen hybrids (Odae19 × Bonghyeon4 F1) established in the research forest of Seoul National University. After DNA extraction, paternity was confirmed using five microsatellite markers, and only the individuals for which paternity was confirmed were used for the analysis. The DNA was cut using restriction enzymes and the obtained DNA fragments were prepared using a GBS library and sequenced. The analyzed results were sorted using Populus trichocarpa as a reference genome. Overall, 58,040 aligned single-nucleotide polymorphism (SNP) markers were identified, 17,755 of which were used for mapping genetic linkages. The genetic linkage map was divided into 19 linkage groups, with a total length of 2,129.54 cM. The analysis failed to identify any growth-related QTLs, but a gene assumed to be related to recovery from insect damage was identified on linkage group (chromosome) 4 through genome-wide association study.

• Journal of the Korean Society of International Agriculture
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• v.31 no.3
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• pp.249-254
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• 2019

'Japonica 6' is a japonica rice variety developed from a cross between 'MS11', the beginning variety adaptable to tropical region, and 'IR86743-28-1-4', an elite line of high yield and good plant type by a Korea(RDA)-IRRI cooperative breeding program at IRRI in 2017. The growth duration of 'Japonica 6' is 121 days from sowing to harvest. It is 10 days later than that of the check variety 'MS11'. The culm length of 'Japonica 6' is 70 cm, and 1,000-brown rice grain weight is 26.7 g. It has a shorter culm and a larger grain. size than that of MS11. 'Japonica 6' is moderately resistant to blast disease but susceptible to bacterial blight, tungro virus and plant hoppers. The milled rice recovery rate of 'Japonica 6' is improved than that of 'MS11'. The head rice rate of 'Japonica 6' is significantly higher than that of 'MS11'. Yield of 'Japonica 6' is averagely 3.59 MT/ha of milled rice in 5 areas of the Philippines. The 'Japonica 6' was registered in Philippines and would be adaptable to the diverse regions of tropical Asia (Registration No in Philippines. BPI-NSIC-2017-Rc 484SR).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.2
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• pp.97-114
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• 1977

The fresh water prawn, Macrobrachium rosenbergi(de Man) is a very common species in Indopacific region, which inhaits both fresh and brackish water in low land area, most of rivers and especially aboundant in the lower reaches which are influenced by sea water. It is one of the largest and commercial species of genus Macrobrachium, which is commonly larger than $18\~21cm$ in body length, from the basis of eye-stalked to the distal of telson. As a part of the researches in order to investigate the possibilities on transplantation and propagation of this species, this work dealt with the problems on the effects of chlorinities upon zoeal larvae and post-larvae 1). metamorphosis rate and optimum chlorinity for metamorphosis to post-larve, 2). tolerance and comparative survival rate on various chlorinties, from fresh water to sea water $(19.38\%_{\circ}\;Cl)$, which reared for six days upon each stage of zoeal larvae, 3). accomodation rate on chlonities which reared for twelve days after transmigration into variant chlorinities of the range from $3.68\%_{\circ}$ Cl to $1.53\%_{\circ}$ Cl in the way of rearing of the range from $3.82\%_{\circ}$ Cl to $11.05\%_{\circ}$ upon each stage of zoea, 4). tolerance on both of fresh and sea water upon zoeal larva and post-larva under the condition of $28^{\circ}C{\pm}1$ in temperature and feeding on Artenia salina nauplii, 5). relationship between various chlorinities and grwth of post-larvae under the condition of $28^{\circ}C$ in tmperature and feeding on meat of clam. Thus these investigations were performed in order to grope for a comfortable method on seedmass production. Up to the present, the study on the effects of chlorinity upon earlier zoeal larvae and post-larvae of Macrobrachium species has been scarcely performed by workers with the exception of Lewis(1961) and Ling (1962,, 1967), even so their works were not so detailed. On the other hand, larvae of several species of this genus were reared at the water which mixed sea water so as to carry out complete metamorphosis to post-larva by workers in order to investigate on earlier 1 arval and earlier post-larval development, such as Macrobrachium lamerrei (Rajyalakshmi, 1961), M. rosenbergi and M. nipponense (Uno and Kwoa, 1969; Kwon and Uno, 1969), M. acanthurs (Choudhury, 1970; Dobkin, 1971), M. carcinus(Choudhury, 1970), M. formosense(Shokita, 1970), M. olfersii (Duggei et al., 1975), M. novaehallandiae (Greenwood et al., 1976), M. japonicum (Kwon, 1974) and M. lar (Shokita, personal communication), and there fore it is regarded that chlorinity is, generally, one of absolute factors to rear zoeal larvae of brackish species of Macrobrachium genus. Synthetic results on this work is summarized as the follwings: 1) Zoeal larvae required different chlorinities to grow according to each stage, and generally, it is regarded that optimum range of living and growing is from $7.63\%_{\circ}Cl\to\;7.63\%_{\circ}Cl$, and while differences of metamorphsis rate, from first zoea to post-larva, is rarely found in this range, and however it occurs apparently in both of situation at $7.63\%_{\circ}Cl$ below and $16.63\%_{\circ}Cl$ above and moreover, metamorphosis rate is delayed somewhat in case of lower chlorinity as compared with high chlorinity in these situations. 2) Accomodation in each chlorinity on the range, from fresh water to sea water, is different according to larval stages and while the best of it is, generally, on the range from $14.24\%_{\circ}Cl$ to $8.28\%_{\circ}Cl$ and favorite chlorinity of zoea have a tendency to remove from high chlorinity to lower chlorinity in order to advance larval age throughout all zoeal stages, setting a conversional stage for eighta zoea stage. 3) Optimum chlorinity of living and growth upon postlarvae is on the range of $4.25\%_{\circ}Cl$ below, and in proportion as approach to fresh water, growth rate is increased. 4) Post-large are able to live better in fresh water in comparison with zoeal larvae, which are only able to live within fifteen hours, and by contraries, post-larvae are merely able to live for one day as compared with ?미 larvar, which are able to live for six days more in sea water $19.38\%_{\circ}Cl\;above$. 5) Also, in case of transmigration into higher and lower chlorinities in the way of rearing in the initial chlorinities $ 3.82\%_{\circ}Cl,\;7.14%_{\circ}Cl\;and\;11.05%_{\circ}Cl$, accoodation rate is a follow: accomodation capacity in ease of removing into higher chlorinities from lower chlorinities is increased in proportion as earlier stages, setting a conversional stage for eighth zoea stage, and by contraries, in case of advanced stages from eighth zoea it is incraesed in proportion as approach to post-larva stage in the case of transmigration into lower chlorinity from higher chlorinity. On the other hand, it is interesting that in case of reciprocal transmigration between two different chlorinitiess, each survival rate is different, and in this case, also, its accomodation in each zoea stage has a tendency to vary according to larval stages as described above, setting a conversional stage for eighth zoea stage. 6) It is likely that expension of radish pigments on body surface is directly proportional to chlorinity during the period of zoea rearing, and therefore it seems like all body surfacts of zoea larvae be radish coloured in case of higher chlorinity. 7) By the differences that each zoeal larvae, postlarvae, juvaniles and adult prawn are required different chlorinity for inhabiting in each, it is regarded that this species migrats from up steam to near the estuary of the river which the prawns inhabits commonly in natural field for spawning and growth migration. 8) It had better maintainning chlorinities according to zoeal stage for a comfortable method on seed-mass production that earlier larva stages than eighth zoea are maintained on the range from $8\%_{\circ}Cl\;to\;12\%_{\circ}Cl$ to rear, and later larva stages than eighth zoea, by contraries, are gradually regula ted-to love chlorininity of the range from $7\%_{\circ}Cl\;to\;4\%_{\circ}Cl$ according to advance for post-larva stage.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.2
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• pp.116-120
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• 1991

Silage productivity of two sorghum hybrids. Pioneer(P) 931 and P 956, and green fodder productivity of a sorghum-sudangrass hybrid, P 988, were tested at four levels of seeding rates (1, 2, 3, and 4 kg/lOa). The 1st-cut of sorghum hybrids of P 931 and P 956 was made at milk ripe stage for silage on July 22 and 31, respectively and regrowth was harvested on Oct. 13. The 1st-and 2nd-cut of a sorghum-sudangrass hybrid were made at flag leaf emerging stage for green fodder on July 26 and Aug. 16 and 3rd-cut was harvested on Oct. 13. The results obtained are summarized as follows:1. Growth stage, culm length or plant height, and percent dry matter (DM) were similar among the seeding rates. Percent DM of sorghum hybrids ranged 26.9-31.2% regardless hybrids and t ~ m e of harvest. However, in the sorghum-sudangrass hybrid percent DM of the 1st-cut. 2nd-cut, and 3rd-cut ranged 10.0-10.7% 18.2-19.97% and 24.6-27.8% respectively.2. In sorghum hybrids crude(C) fiber content of P 931 was higher, but nitrogen free extract (NFE) was lower compared with those of P 956 and C. protein and C. fat were similar between two hybrids. However, C. protein and C. ash of sorghum hybrids were lower, but C. fiber and NFE were higher compared with those of a sorghum-sudangrass hybrid and C. fat was similar between two crops.3. Total DM yield was greater in the order of P 931>P 956>P 988. The optimum seeding rate for both silage yield of sorghum hybrids and green fodder of a sorghum-sudangrass hybrid was 2-4 kg/lOa. However, yield of the 1st-cut tended to increase as seeding rate increased.

• Journal of Bio-Environment Control
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• v.19 no.2
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• pp.77-81
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• 2010

The effects of $CO_2$ concentration on fruit-body formation and yield of Pleurotus ferulae (KME65003) mushroom were examined in the growing facilities for bottle cultivation. The $CO_2$ concentration levels in the growing facilities were 500 ppm, 1000 ppm, 1500 ppm and 2000 ppm of $CO_2$, controlled by different ventilation amount. Yield of fruit body was highest of 102.4 g/bottle at 1000 ppm treatment and lowest of 75.1 g/bottle at 2000 ppm. As the $CO_2$ concentration increased up to 2000 ppm, the first pinhead formation and fruit-body growing period took longer, so total growing period took 16 days at 500 ppm, but 23 days at 2000 ppm. The number of pinhead formation was highest of 12.2/bottle at 1500 ppm and valid stipes was highest of 2.8/bottle at 1000 ppm. Fruit body characteristics such as pileus and stipe diameter, and stipe length were not significant at different $CO_2$ concentration. The fruit body ratio of 20~50 g range among the whole fruit body which was classified by weight was highest of 60.3% at 1000 ppm. As a result, the suitable $CO_2$ concentration of growth and yield of Pleurotus ferulae was showed as 1000 ppm.

• Journal of Korean Society of Forest Science
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• v.82 no.4
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• pp.366-380
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• 1993

Quercus acutissima ectomycorrhizae were classified as apical type, linear type, clavate type, diffuse type, pyramidal type, coralloid type, and nodular type. The surface texture of the fungal mantle at the initial stage of mycorrhizal formation was velvety. The surface texture of Pisolithus tinctorius(Pt) mycorrhizae at 30 September was well-developed felty mantle, Yellowish white. Except Pt all mycorrhizae formed by ectomycorrhizal fungi used to experiment were white with felty mantle. Mycorrhizae at the initial stage of mycorrhizae formation were creamy or creamy brown and swelled with thin mantle. Transverse and longitudinal sections showed radially-elongated cortical cell layers and epidermal cell with Hartig net. The transversal wideth of radially-elongated cortical and epidermal cells in the mycorrhizae with thick mantle on 30 September did not different with the mycorrhizae with thin mantle on the initial stage. Pt #250 formed coralloid mycorrizae but Pt KJ-1 did not although they are same species. On the mean length of linear type ectomycorrhizae of Pt KJ-1(2.21mm) was 1.5 times longer than that of Pt #250(1.32mm). The total dry weight of seedlings inoculated with Pt KJ-1, Pt #250, Lycoperdon pedicellatum, Scleroderma verrucosum were significantly heavier than those of suillus granulatus, Laccaria laccata.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.768-776
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• 2010

This study was conducted to predict number and fresh weight of leaves, and total leaf area of a single-stemmed rose 'Vital' based on the accumulated thermal units, and to develop a model of shoot development for the prediction of the time when the flowering shoot reaches a phenological stage in a plant factory system. The base temperature ($T_b$), optimum temperature ($T_{opt}$), and maximum temperature ($T_{max}$) were estimated by regressing the rate of shoot development against the temperature gradient. The rate of shoot development ($R$, $d^{-1}$) for the phase from cutting to bud break (CT-BB) was best described by a linear model $R_b$ ($d^{-1}$) = -0.0089 + $0.0016{\cdot}temp$. The rate of shoot development for the phase from bud break to harvest (BB-HV) was fitted to the parabolic model $R_h$ ($d^{-1}$) = $-0.0001{\cdot}temp^2$ + $0.0054{\cdot}temp$ - 0.0484. The $T_b$, $T_{opt}$, and $T_{max}$ values were 5.56, 27.0, and $42.7^{\circ}C$, respectively. The $T_b$ value was used in the thermal unit computations for the shoot development. Number of leaves, leaf area (LA), and leaf fresh weight showed sigmoidal curves regardless of the cut time. The shoot development and leaf area model was described as a sigmoidal function using thermal units. Leaf area was described as LA = 578.7 $[1+(thermal units/956.1)^{-8.54}]^{-1}$. Estimated and observed shoot length and leaf fresh weight showed a reasonably good fit with 1.060 ($R^2=0.976^{***}$) and 1.043 ($R^2=0.955^{***}$), respectively. The average thermal units required from cutting to transplant and from transplant to harvest stages were $426{\pm}42^{\circ}C{\cdot}d$ and $783{\pm}24^{\circ}C{\cdot}d$, respectively.

• Korean Journal of Agricultural Science
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• v.14 no.1
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• pp.1-15
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• 1987

This experiment was conducted to investigate the effect of nitrogen top-dressing and Jangyeopkong was planted under two different seeding time (single cropping-May 15, after barley cropping-June 18), four levels of nitrogen top-dressing (0, 3, 6, 9 kg/10a) and two times of nitrogen top-dressing (Hilling time, Flowering Time). The results obtained are summarized as follow: 1. The days to flowering and maturity were delayed a day longer in hilling times than flowering times of nitrogen top-dressing. 2. The number of nodes of main stem and length of internodes didn't show significance among treatments. But, the number of nodes of branches was much higher when the soybean was planted on May 15, and were higher hilling time than flowering time as the amount of nitrogen top-dressing increased. Especially, the number of nodes of branches was high when 6kg of nitrogen was applied during hilling time. 3. The fresh and dry weight of stem and leaves at 10, 25 and 40 days after flowering were increased by increasing the amount of nitrogen top-dressing. More apparent effect of nitrogen was attained high significant when nitrogen was applied at the time of hilling rather than flowering time. 4. The number and fresh weight of nodule, and dry weight were apparently decreased after barley and were decreased according to the increasing the amount of nitrogen top dressing. The degrees of decreasing was more apparent in the hilling time than in the flowering time. 5. The number of pods per plant, and number and weight of grain per plant were higher when the soybean was planted on May 15, the amount of top dressing increased and hilling time rather than flowering time. Especially, yield component were highest when 6kg of nitrogen was applied during hilling time. Also, the grain yield per 10a showed high significance among treatment, and were high when 6kg of nitrogen was applied during hilling time.

• Journal of Aquaculture
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• v.18 no.2
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• pp.107-114
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• 2005

Clownfish are important and very popular fish in the ornamental aquarium industry. Demand for the fish is increasing dramatically. The present study was conducted to verify methods of broodstock management, patterns of spawning, rates of egg hatching and estimates of larval growth fur the saddleback clownfish, Amphiprion polymnus. Spawning occurred 8 times between August 2002 to June 2004 with 2 females and 1 male participating. Fertilized eggs were separated by an adhesive matrix and were oval in shape. The eggs were $2.46{\pm}0.13mm$ in size as measured along the longest axis. The percentage of fertilized eggs was 96.7%. Hatching was observed seven days post-spawning and hatching rate was 85.5%. The sizes of the newly-hatched larvae were $4.58{\pm}0.21mm$ TL (total length). Larvae had an open mouth and anus, and an oval yolk sac. At the 1 st day after hatching, the sizes of the larvae were $4.90{\pm}0.35mm$ TL. The larvae began to eat rotifers after complete yolk absorption. On the 5th day post-hatch, larvae were $5.88{\pm}0.31mm$ TL with complete fins and the survival rate was 48.6%. At 8 days after hatching, a band began to appear on head and back of the larvae indicating the beginning of metamorphosis. Metamorphosis was completed at an average TL of $15.00{\pm}2.12mm$ on the 23rd day after hatching. By the 45th day after hatching, juveniles averaged $22.76{\pm}3.22mm$ TL and survival rate was 28.4%.

• Food Science and Preservation
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• v.20 no.2
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• pp.182-190
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• 2013

This study investigated the quality characteristics between spring cultivars of Kimchi cabbage(Brassica rapa L. ssp. pekinesis). We measured the weight, length, width, formation index, midrib thickness and moisture contents of fresh Kimchi cabbage for characteristics of growth. And we analyzed the free sugar, amino acid, organic acid, mineral, pectin and cellulose contents of fresh Kimchi cabbage. The hardness and firmness were measured for texture of fresh Kimchi cabbage. The weight of 'K-power' cultivar was the highest than other cultivars. The 'Jeongsang' cultivars was the thinnest midrib thickness in cultivars, but it was not significantly different. The free sugar levels of spring cultivars was the highest in 'Chunkwang'. Malic acid content of 'Jeongsang' was significantly different among spring cultivars. Also amino acid content of 'K-power' and 'Chunkwang' were significantly different among spring cultivars Mineral content in 'K-power' and 'Bomaknorang' were greater than that of other cultivars. Especially Na, Ca and Mg contents of 'K-power' and 'Bomaknorang' were higher four times than that of other cultivars. Pectin content of 'Jeongsang' was higher than that of other cultivars, but it was not significantly different. Hardness and Firmness were not significantly different among spring cultivars.