• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.3
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• pp.99-108
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• 2016

The shuttle breeding of Korean winter wheat has been able to develop high-yielding and day-length-intensive varieties with a wide range of ecologic adoption. However, the phenology of winter wheat has been changed due to recent rises in the winter temperature of Toluca and increasing frequency of high temperatures. We defined two wheat groups (group II and III) with vernalization and evaluated the impact of cold exposure duration and heading ratio due to changes in sowing dates by measuring changes in cold exposure duration and corresponding heading states of each group. The wheat cultivars were sown on three dates in two years. The cold exposure requirement of wheat sown on 6 November 2013 was unfulfilled. The cold exposure requirement of wheat sown on 22 November and 6 December 2013 was fulfilled. However, in 2014, the cold exposure requirement of wheat sown on 5 and 20 November was fulfilled, but that of wheat sown on 5 December was unfulfilled. The differences for the two early November sowings were because winter temperature rises, which caused high temperatures in 2013, whereas early November 2014 saw normal temperatures for the area. The heading ratio of group II did not show a clear difference among the three sowing dates, while the heading ratio of group III was reduced by about half. This implies that the efficiency of shuttle breeding of group III will be high since it showed strong sensitivity to changes in sowing dates. We calculated future sowing dates of each group under near future climate scenarios; the future available sowing dates of group II were projected, but the dates of group III were never estimated in the temperature rise scenario in Toluca. Our findings suggest that change of sowing dates should be considered in the strategy for shuttle breeding of Korean winter wheat.

• Korean Journal of Environmental Agriculture
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• v.37 no.2
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• pp.79-86
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• 2018

BACKGROUND: Chinese cabbage biosynthesizes various phytochemicals including carotenoids and glucosinolates. Environmental stress has a major effect on the growth and yields of vegetables, and can significantly affect nutritionally important phytochemicals. Phytochemicals of plants are influenced by light, temperature, carbon dioxide, and growing conditions. The aim of this study was to investigate the effect of various light sources on carotenoid and glucosinolate contents in Chinese cabbage. METHODS AND RESULTS: [Experiment I] Set the control (field control, FC) on the ground. Using acrylic sunlight, experiments were set up transparency box (field transparency, FT), red box (field red, FR) and blue box (field blue, FB). [Experiment II] Set the control (chamber control, CC) in the greenhouse. Using plant growth chamber with artificial light, experiments were set up LED red (chamber red, CR), LED blue (chamber blue, CB), LED mixed red+blue (chamber red+blue, CRB) and fluorescent (chamber fluorescent, CF). After plant growth, Chinese cabbage was harvested at 110 days after sowing (DAS). The status of plants growth (leaf length, width, fresh weight etc.) was immediately investigated. Carotenoid and GSL contents were analyzed by HPLC. [Experiment I] Results documented that the ranges of total carotenoid contents were 25.39 ~ 58.80 mg/kg dry wt for lutein, 0.84~ 4.22 mg/kg dry wt for zeaxanthin, and 3.85~18.71 mg/kg dry wt for ${\beta}$-carotene. Lutein was the highest for the content and the largest for the variation as well. [Experiment II] Results documented that the ranges of total carotenoid contents were 24.66~137.96 for lutein, 2.51~20.65 for zeaxanthin, and 8.40~49.80 mg/kg dry wt for ${\beta}$-carotene. The total carotenoid contents of CR (156.62) and CB (115.90) were 1.6~2.3 times larger than the other treatments, and ${\beta}$-carotene content was about twice as high as that of the other treatments on the CR (38.74 mg/kg dry wt.). [Experiment I] Total GSL content was the highest in FT (19.76) that was higher 1.7 times than the lowest treatment ($11.39{\mu}mol/g\;dry\;wt$.). [Experiment II] The total content of GSL was highest in CRB (4.19) and lowest in CF ($2.88{\mu}mol/g\;dry\;wt$.). In the CRB, total GSL contents ($4.19{\mu}mol/g\;dry\;wt$.) was the highest. CONCLUSION: Total and individual carotenoid and GSL contents in Chinese cabbage show significant differences under different light sources. Red and blue lights contribute to significant carotenoids expression and antioxidant activity for nutrition and health benefits. These results concluded that the introduction of varying lights affected the synthesis of important nutrient compounds in Chinese cabbage. It is predicted that the application of good light source enhances the accumulation of functional compounds.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.3
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• pp.160-166
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• 2004

This study was carried out to get the basic informations regarding the varietal variations for the physicochemical properties such as protein content, amylose content, fatty acid content, grain quality values and color properties such as lightness value, chroma and hue for the 164 recombinant inbred lines(RILs) of Milyang 23 and Gihobyeo(M/G) at the experimental farm in the Sangji University. The principal component analysis and heritability study were conducted for this experiments. The rapidity of grain filling(RCF) for the 164 M/G RILs could be classified into four groups such as slow maturing group less than 41％, mid-slow maturing group 41∼60％, fast maturing group 61∼80％ and very fast maturing group more than 81％ based on the rapidity of grain filling rate. The slow maturing group of RGF showed a little bit higher protein content 9.1％, compared to the other RGF groups. However, the amylose content of all the RGF groups revealed the same content by the groups. The very fast maturing group of RGF showed longer grain length in brown rice compared to other RGF varietal groups, in case of grain width in brown rice showed shorter than any other groups. The alkali digestive value which was so much related to gelatinization temperature showed 3.40 degree at fast maturing group of RGF in M/G RILs. However, the very fast maturing group of RGF revealed 4.31 degree of alkali digestive value. The principal component analysis was performed by the chemical and color properties such as quality value, protein content, amylose content, alkali digestive value, fatty acid content, lightness value, chroma and hue for M/G RILs. The first principal component was able to explained upto 36％ to total informations. It was corresponded to quality value, protein content, amylose content, fatty acid content, lightness value and a-value(green -1 red). The characters regarding grain quality showed high heritable properties more than 75％ of heritability, but color characters appeared relatively lower heritability compared to grain quality.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.26 no.3
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• pp.174-183
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• 2014

Seabed beneath and near coastal structures may undergo large excess pore water pressure composed of oscillatory and residual components in the case of long durations of high wave loading. This excess pore water pressure may reduce effective stress and, consequently, the seabed may liquefy. If liquefaction occurs in the seabed, the structure may sink, overturn, and eventually increase the failure potential. In this study, to evaluate the liquefaction potential on the seabed, numerical analysis was conducted using the expanded 2-dimensional numerical wave tank to account for an irregular wave field. In the condition of an irregular wave field, the dynamic wave pressure and water flow velocity acting on the seabed and the surface boundary of the composite breakwater structure were estimated. Simulation results were used as input data in a finite element computer program for elastoplastic seabed response. Simulations evaluated the time and spatial variations in excess pore water pressure, effective stress, and liquefaction potential in the seabed. Additionally, the deformation of the seabed and the displacement of the structure as a function of time were quantitatively evaluated. From the results of the analysis, the liquefaction potential at the seabed in front and rear of the composite breakwater was identified. Since the liquefied seabed particles have no resistance to force, scour potential could increase on the seabed. In addition, the strength decrease of the seabed due to the liquefaction can increase the structural motion and significantly influence the stability of the composite breakwater. Due to limitations of allowable paper length, the studied results were divided into two portions; (I) focusing on the dynamic response of structure, acceleration, deformation of seabed, and (II) focusing on the time variation in excess pore water pressure, liquefaction, effective stress path in the seabed. This paper corresponds to (II).

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.26 no.3
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• pp.160-173
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• 2014

Seabed beneath and near coastal structures may undergo large excess pore water pressure composed of oscillatory and residual components in the case of long durations of high wave loading. This excess pore water pressure may reduce effective stress and, consequently, the seabed may liquefy. If liquefaction occurs in the seabed, the structure may sink, overturn, and eventually increase the failure potential. In this study, to evaluate the liquefaction potential on the seabed, numerical analysis was conducted using the expanded 2-dimensional numerical wave tank to account for an irregular wave field. In the condition of an irregular wave field, the dynamic wave pressure and water flow velocity acting on the seabed and the surface boundary of the composite breakwater structure were estimated. Simulation results were used as input data in a finite element computer program for elastoplastic seabed response. Simulations evaluated the time and spatial variations in excess pore water pressure, effective stress, and liquefaction potential in the seabed. Additionally, the deformation of the seabed and the displacement of the structure as a function of time were quantitatively evaluated. From the results of the analysis, the liquefaction potential at the seabed in front and rear of the composite breakwater was identified. Since the liquefied seabed particles have no resistance to force, scour potential could increase on the seabed. In addition, the strength decrease of the seabed due to the liquefaction can increase the structural motion and significantly influence the stability of the composite breakwater. Due to limitations of allowable paper length, the studied results were divided into two portions; (I) focusing on the dynamic response of structure, acceleration, deformation of seabed, and (II) focusing on the time variation in excess pore water pressure, liquefaction, effective stress path in the seabed. This paper corresponds to (I).

• Horticultural Science & Technology
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• v.29 no.5
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• pp.456-460
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• 2011

This study was carried out to compare the pattern of mutant variation and to evaluate the characteristics of mutants obtained by gamma irradiation in rose 'Kardinal'. Forty four rooted cuttings of 'Kardinal' were irradiated at 70 Gy gamma-ray dose from a $^{60}Co$ source to induce mutants in 2002. The irradiated plants were planted in field, and observed spotting of petal color mutants from 2002 to 2004. Four different kinds of mutant twigs with each different color flower were obtained from the irradiated 'Kardinal' with red petal. After being identified to be a stable mutant from 2004 to 2008, each mutant line propagated by cutting was hydroponic-cultured to evaluate the characteristics in the greenhouse from 2008 to 2009. Four mutant lines obtained from 'Kardinal' with red petal (Red group, 44A, 45B) include KA1 with light pink petal (Red group, 55B-55D), KA2 with pink petal (Red group, 63A-63B), KA3 with deep pink (Red purple, N57A-N57C), and KA4 with orange red (Red group, 43A-43B). Diameters of each flower in four mutant lines were different from 'Kardinal'. The line KA1 was 9.5 cm wide, and it showed the smallest diameter when compared to other mutants. While the line KA2 was the largest one with 12.5 cm 'Kardinal'. Petal number per flower was also variable among the mutants. The line KA2 had 39.8 petals being the largest number among the mutants, while the line KA1 was the lowest one compared to 35.5 petals of 'Kardinal'. Petal color was measured by using colorimeter. Brightness (L) measured at each petal of four mutants increased more than 'Kardinal'. CIE Lab values, a and b decreased more than 'Kardinal' at the petal color of three mutants except the line KA4. Characteristics of shoot, leaf, etc. from four mutants were also different from the ones of 'Kardinal'. The line KA1 was shortest in shoot, node and peduncle length, and lowest in prickle number. The reverse side of leaves was reddish green color in 'Kardinal' as well as the line KA4, but green color in the line KA1, KA2, and KA3.

• Korean Journal of Weed Science
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• v.31 no.2
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• pp.134-145
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• 2011

The objectives of this study were to investigate fitness difference in growth and rice yield in herbicide-transgenic rice overexpressing Myxococcus xanthus and Arabidopsis thaliana protoporphyrinogen oxidase (Protox) genes and non-transgenic rice. We also aimed to determine whether these fitness differences are related to ALA synthesizing capacity, accumulation of terapyrroles, reactive oxygen species, lipid peroxidation, and antioxidative enzymes at different growth stages of rice. Plant height of the transgenic rice overexpressing M. xanthus (MX) and A. thaliana (AP37) Protox genes at 43, 50, and 65 days after transplanting (DAT) was significantly lower than that of WT. Number of tiller of PX as well as MX and AP37 at 50 and 65 DAT was significantly lower than that of WT. At harvest time, culm length and yield of MX, PX and AP37 and rice straw weight of MX and AP37 were significantly low compared with WT. The reduction of yield in MX, PX, and AP37 was caused by spikelets per panicle and 1000 grain weight, ripened grain, spikelets per panicle, 1000 grain weight, and ripened grain, respectively. On the other hand, 135 the reduction of yield in MX, PX, and AP37 was also observed in another yearly variation experiment. The reduction of rice growth in MX, PX, and AP37 was observed in seedling stage as well as growth duration in field. There were no differences in tetrapyrrole intermediate Proto IX, Mg-Proto IX and Mg-Proto IX monomethyl ester, reactive oxygen species ($H_2O_2$ and ${O_2}^-$), MDA, antioxidative enzymes (SOD, CAT, POX, APX, and GR) and chlorophyll between transgenic lines and wild type, indicating that accumulated tetrapyrrole intermediate and other parameters were not related to growth reduction in transgenic rice. However, ALA synthesizing capacity in MX, PX, and AP37 at one day after exposure to light and 52 DAT was significantly lower than that of WT. Further study is required to elucidate the mechanisms underlying the growth and yield difference between transgenic and WT lines.

• Applied Biological Chemistry
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• v.9
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• pp.119-124
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• 1968

In order to learn the effect of timing and rate of potash fertilization in the rice plant nursery on the root growth and the vegetative growth of later stage a pot experiment was carried out employing 'Jaekun' a rice variety. Potassium Chloride was applied at the rate of $0{\sim}100g\;K_{2}O/3.3m^2$ right before, and 30 days after seeding. Forty-day old seedlings were transplanted three times successively at the one week intervals with the roots cut each time. Each subject was observed in rooting and other useful traits. A part of seedlings after the third root scission were cultured intact thereafter and the yield characters examined. The results were shown as: 1. The rate of sound seedlings was high in the case that a small amount of potassium was applied as the basic placement while the application of the fertilizer over $75g/3.3m^2$ (as $K_{2}O$) yielded a far less crops. 2. The plant height, number of tillers, number of leaves, and grass weight increased as the amount of potassium was elevated. However, the application of $50g\;K_{2}O/3.3m^2$ in the basic placement and that of $75g\;K_{2}O/3.3m^2$ were the peaks over which the above mentioned characters were weakened. 3. As the amount of potassium was increased the increment in number of rooting was notable, especially when the scission of roots was repeated within the limit of $50{\sim}75g\;K_{2}O/3.3m^2$. 4. In the maximum root newly shooted length indicated was about the same tendency although no statistical significance was observed. 5. The plant height, number of tillers, and variation of weight between grass and root indicated a similar tendency as the number of root shoot. 6. The differences in number of ears, grain yield, and weight of straw between the treatments were not so great but showed somewhat similar trend as in the growth of transplanted plants. In the treatment-100g $K_{2}O/3.3m^2$ the yield (ears, grain and straw) decreased as in the non-fertilized.

• The Journal of the Acoustical Society of Korea
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• v.13 no.6
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• pp.75-82
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• 1994

The ray paths and travel times of sound wave in the ocean depend on the physical properties of the propagating media. Ocean Acoustic Tomography(OAT), which is inversely estimate the travel time variations between fixed sources and receivers the physical properties of the corresponding media can he understood. To apply ocean survey technology by using the OAT, the tomographic procedure requires forward problem that variation of the travel times be identified with the variability of the medium. Also, received signals must be satisfied the necessary conditions of ray path stability, identification and resolution in order for OAT to work. The canonical ocean has been determined based on the historical data and its travel time and ray path are used as reference values. The sound speed of canonical ocean in the East Sea is about 1523 m/s at the surface and 1458 m/s at the sound channel axis(400m). Sound speeds in the East Sea are perturbed by warm eddy whose horizontal extension is more than 100 km with deeper than 200 m in depth scale. In this study, an acoustic source and receiver are placed at the depth above the sound channel axis, 350 m, and are separated by 200 km range. Ray paths are identified by the ray theory methed in a range dependent medium whose sound speeds are functions of a range and depth. The eigenray information obtained from interpolation between the rays bracketing the receiver are used to simulate the received signal by convolution of source signal with the eigenray informations. The source signal is taken as a 400 Hz rectangular pulse signal, bandwidth is 16 Hz and pulse length is 64 ms. According to the analysis of the received signal and identified ray path by using numerical model of underwater sound propagation, simulated signals satisfy the necessary conditions of OAT, applied in the East Sea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.2
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• pp.194-201
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• 1995

In order to make clear the resistance of bag nets, the resistance R of bag nets with wall area S designed in pyramid shape was measured in a circulating water tank with control of flow velocity v and the coefficient k in $R=kSv^2$ was investigated. The coefficient k showed no change In the nets designed in regular pyramid shape when their mouths were attached alternately to the circular and square frames, because their shape in water became a circular cone in the circular frame and equal to the cone with the exception of the vicinity of frame in the square one. On the other hand, a net designed in right pyramid shape and then attached to a rectangular frame showed an elliptic cone with the exception of the vicinity of frame in water, but produced no significant difference in value of k in comparison with that making a circular cone in water. In the nets making a circular cone in water, k was higher in nets with larger d/l, ratio of diameter d to length I of bars, and decreased as the ratio S/S_m$ of S to the area $S_m$ of net mouth was increased or as the attack angle 9 of net to the water flow was decreased. But the value of ks15m was almost constant in the region of S/S_m=1-4$ or $\theta=15-90^{\circ}$ and in creased linearly in S/S_m>4 or in $\theta<15^{\circ}$ However, these variation of k could be summarized by the equation obtained in the previous paper. That is, the coefficient $k(kg\;\cdot\;sec^2/m^4)$ of bag nets was expressed as $$k=160R_e\;^{-01}(\frac{S_n}{S_m})^{1.2}\;(\frac{S_m}{S})^{1.6}$$ for the condition of $R_e<100$ and $$k=100(\frac{S_n}{S_m})^{1.2}\;(\frac{S_m}{S})^{1.6}$$ for $R_e\geq100$, where $S_n$ is their total area projected to the plane perpendicular to the water flow and $R_e$ the Reynolds' number on which the representative size was taken by the value of $\lambda$ defined as $$\lambda={\frac{\pi d^2}{21\;sin\;2\varphi}$$ where If is the angle between two adjacent bars, d the diameter of bars, and 21 the mesh size. Conclusively, it is clarified that the coefficient k obtained in the previous paper agrees with the experimental results for bag nets.