• The Journal of the Convergence on Culture Technology
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• v.7 no.2
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• pp.339-343
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• 2021

This study was conducted to compare the shoot development and fruit characteristics on fruit bearing branch (FBB) according to the fruiting level (FLs: FL-Low, -Middle, -High) of peach 'Cheonhong'. The number of shoots per FBB according to the FLs were most distributed in 1-2 (42%) of FL-Low, 1 (47%) of FL-Middle and 1 (42%) of FL-High. And fruit weight and soulable solide content were 210-270g (50%) and 10-12Brix (44%), 180-240g (60%) and 10-12Brix (59%), 180-240g (60%) and 11-13Brix (48%), respectively. In addition, only FL-High showed a linear regression correlation between fruit weight and number of shoots. And a linear regression equation of y=0.0126x+8.1857 (R²=0.1964, P≤0.01) is shown between the souble solid content (y) and the fruit weight (x).

• Journal of Plant Biotechnology
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• v.45 no.4
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• pp.382-391
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• 2018

The objective of this study was to determine the most effective medium condition of shoot proliferation and root formation for the efficient in vitro micropropagation of M.26 (Malus pumila Mill). Simple sequence repeat (SSR) markers were used to analyze the genetic diversity of micro-propagated and greenhouse grown M.26. Shoot proliferation was carried out in MS (Murashige and Skoog) containing benzyladenin (BA, $0.5{\sim}5.0mg{\cdot}L^{-1}$) and thidiazuron (TDZ, $0.01{\sim}0.1mg{\cdot}L^{-1}$). The highest number of shoots (10.67 shoots per explant) was induced by adding BA at a concentration $1.0mg{\cdot}L^{-1}$. TDZ treatments caused higher hyperhydricity rate in cultured explants than in BA treatments. There was no significant effect of both BA and auxin on shoot proliferation, and the optimum proliferation medium for M.26 was MS medium containing $1.0mg{\cdot}L^{-1}$ BA. To find a suitable medium composition for shoot rooting, we tested different concentrations indole-3-butyric acid (IBA) and ${\alpha}$-naphthaleneacetic acid ($0.5{\sim}5.0mg{\cdot}L^{-1}$), MS medium (1/4-1), sucrose ($0{\sim}30g{\cdot}L^{-1}$). The shoots showed good rooting on half-strength MS medium containing $1.0mg{\cdot}L^{-1}$ IBA and $15-20g{\cdot}L^{-1}$ sucrose. The rooting rate (100%), number of roots (10.45 ~ 13.60 roots per explant), root length (7.41 ~ 8.33 cm), and shoot length (4.93 ~ 5.38 cm) were good on this medium. Fifteen SSR primers were detected in a total of 30 alleles in 20 micro-propagated plantlets, all SSR profiles from micro-propagated plantlets were monomorphic and similar to greenhouse grown control plantlet M.26 plant. The results indicated that M.26 micro-propagated plantlets were genetically stable.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.3
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• pp.153-157
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• 2019

Salicylic acid (SA) is an essential plant growth regulator that functions as a signaling molecule in plants. The purpose of this study was to clarify how the exogenous application of SA counteracts aluminum stress-induced growth and biomass yield reduction in alfalfa exposed to aluminum (Al) stress. Two-week-old alfalfa seedlings were exposed to a combination of $AlCl_3$ ($0{\mu}M$, $50{\mu}M$ and $100{\mu}M$, respectively) and SA (0.1 mM) for 72 hours. We observed, Al stress-induced plant growth inhibition and forage yield reduction are Al stress-dependent manner. A significant reduction of plant height (42.0-52.9%), leaf relative water content (13.0-21.4%), root length (35.4-48.7%), shoot fresh weight (31.2-25.9%), root fresh weight (15.4-23.3%), shoot dry weight (12.7-22.2%), roots dry weight (47.3-53.5%), were observed in alfalfa. In contrast, SA alleviated the Al-stress and enhanced growth and biomass yield in alfalfa. This study provides useful information concerning the role of SA that counteracts aluminum stress-induced growth and yield reduction in alfalfa.

• Journal of Plant Biotechnology
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• v.41 no.2
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• pp.94-99
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• 2014

This study was conducted to elucidate the effect of light sources and explant types on in vitro shoot multiplication and rooting of a rare and endangered plant Abeliophyllum distichum. Both apical buds and axillary buds were used as explants under 4 different light sources, cool white florescent light (F), 100% blue light-emitting diode (LED) (B), 50% blue and 50% red LED mixture (BR), and 100% red LED (R). Clear difference was observed in terms of shoot proliferation by light sources types but not by position-dependent explant types. Multiple shoot induction rates were enhanced under both B and BR light sources. Spontaneous rooting was induced in shoot induction medium under B light source. Both the rates of rooting and numbers of roots per explant were higher in apical bud explants compared to axillary bud explants. Interestingly R light source stimulated shoot elongation but inhibited root development. Therefore, our results suggest that the use of apical bud explants under B or BR light sources is suitable for in vitro micropropagation of a rare and endangered plant species, Abeliophyllum distichum.

• Korean Journal of Weed Science
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• v.8 no.2
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• pp.182-186
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• 1988

This study was conducted to level up the tolerance of tobacco plant against bialaphos herbicide through tissue culture. The relatively good shoot regeneration from the subcultured calli treated with bialaphos at 0.5 ppm was observed in old the tobacco varieties tested such as NC 82, BY 4 and KA 101. However, at the treatment of bialaphos 1.0 ppm, shoot regeneration was only made in KA 101 variety, showing better regeneration than that of untreated one, When these shoots were transfered to the medium containing of bialaphos 10.0 ppm, the percentage of living shoots (i.e. tolerant plant) was very low, showing 2.43% in NC 82, 2.76% in KA 101 and 0.78% BY 4. Calli were induced and multiplied from leaf petiole of the above tolerant plants even under 2.5ppm of bialaphos, showing an average of 9% in NC 82 and 16% in KA 101 as compared with the untreated control. No calli were induced from tolerant plants as bialaphos concentration increased up to 5.0 ppm. Direct shooting from leaves of the above tolerant plants, that is selected at 10.0ppm of bialaphos treatment, was observed even under 10.0ppm of bialaphos treatment both in NC 82 and in KA 101 varieties, indicating that tolerance of tobacco plants against bialaphos can be greatly increased.

• Journal of Plant Biotechnology
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• v.35 no.2
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• pp.133-140
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• 2008

The modification of DNA and histone plays an important role for gene expression in plant development. The objective of this research is to observe the effects of methylation on the gene expression during dedifferentiation from rice mature seeds to callus and differentiation from callus to shoots. The embryogenic callus with ability to shoot regeneration was not induced on the N6A medium supplemented with 5-azacytidine and abnormal callus with brown color was formed. When the normal rice callus was placed on the regeneration MSRA medium supplemented with 5-azacytidine, the shoot regeneration was inhibited. The results showed that 5-azacytidine, DNA demethylating agent, had negative effects on normal embryogenic callus formation and shoot regeneration. This suggested that DNA methylation of some genes was required for normal cell dedifferentiation and differentiation in tissue culture. The microarray and $GeneFishig^{TM}$ DEG screening were used to observe the gene transcript profile in callus induction and regeneration on N6A (N6 medium + 5-azaC) and MSRA (MS regeneration medium + 5-azaC). Subsets of genes were up-regulated or down-regulated in response to 5-azaC treatments. The genes related with epigenetic regulation, electron transport, nucleic acid metabolism and response to stress were up and down regulated. The different expression of some genes (germin like protein etc.) during callus induction and shoot regeneration was confirmed using RT-PCR and northern blot analysis.

• Korean Journal of Plant Resources
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• v.25 no.2
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• pp.277-284
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• 2012

In the present study, the effects of plant growth regulators on adventitious shoot and root formation of various explants of $in$ $vitro$ seedlings of $Solanum$ $nigrum$ L. were investigated to determine the optimum conditions for the high-efficiency plant regeneration of this species. The formation of adventitious shoots was higher in leaf explants than in cotyledon, hypocotyl, or epicotyl explants at low concentrations (0.5~2.0 mg $L^{-1}$ ) of 6-benzylaminopurine (BAP). The number of adventitious shoots and the shoot length were also higher in both leaf and cotyledon explants. In particular, 2.0 mg $L^{-1}$ BAP was most effective for stimulating the induction and multiplication of adventitious shoots. In terms of root formation and root development from shoots that were separated from multiple shoots, indole butyric acid (IBA) and indole acetic acid (IAA) were more effective than ${\alpha}$-naphthalene acetic acid (NAA). The percentage of rooting as well as the number of roots per shoot (4.0), root length (7.82 cm), and shoot length (8.76 cm) was highest on MS media supplemented with 0.05 mg $L^{-1}$ IAA. Furthermore, 100% of the regenerated plantlets survived when transplanted to compost soil. These results suggest that leaf explants are the best source for the high-efficiency regeneration of $S.$ $nigrum$ L., and that 2.0 mg $L^{-1}$ BAP and 0.05 mg $L^{-1}$ IAA are the best conditions for shoot and root induction, respectively.

• Korean Journal of Medicinal Crop Science
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• v.20 no.2
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• pp.101-107
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• 2012

Effects of nitrogen (N), phosphorous (P) and potassium (K) on the shoot and bulb growth of wild garlic ($Allium$ $victorialis$ var. $platyphyllum$) were studied by adopting $in$ $vitro$ culture. These macronutrients influenced the growth of both the shoot and bulb of garlic depending upon their application doses. A minimum of 3% potassium nitrate ($KNO_3$) as a source of nitrogen was found to be critical for shoot elongation while higher concentrations were inhibitory. Garlic bulb growth was profuse on the usual $KNO_3$ strength and sucrose (7%), followed by $KNO_3$ (9.4 mM) supplement. On providing 41.22 mM ammonium nitrate ($NH_4NO_3$) as nitrogen source highest shoot growth was observed while 82.45 mM $NH_4NO_3$ as a source of nitrogen supported high bulb growth. With regard to potassium a good shoot growth was observed in medium that contained 0.31 mM $KH_2PO_4$ and 3% sucrose, while bulb growth was high on 2.5 mM $KH_2PO_4$ and 7% sucrose. These experiments may thus direct the development of excellent growth conditions for the commercial production of edible wild garlic.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.326-331
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• 2018

Crop growth models are useful tools for understanding and integrating knowledge about crop growth. Models for predicting plant height, net photosynthesis rate, and plant growth of quinoa (Chenopodium quinoa Willd.) as a leafy vegetable in a closed-type plant factory system were developed using empirical model equations such as linear, quadratic, non-rectangular hyperbola, and expolinear equations. Plant growth and yield were measured at 5-day intervals after transplanting. Photosynthesis and growth curve models were calculated. Linear and curve relationships were obtained between plant heights and days after transplanting (DAT), however, accuracy of the equation to estimate plant height was linear equation. A non-rectangular hyperbola model was chosen as the response function of net photosynthesis. The light compensation point, light saturation point, and respiration rate were 29, 813 and $3.4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. The shoot fresh weight showed a linear relationship with the shoot dry weight. The regression coefficient of the shoot dry weight was 0.75 ($R^2=0.921^{***}$). A non-linear regression was carried out to describe the increase in shoot dry weight of quinoa as a function of time using an expolinear equation. The crop growth rate and relative growth rate were $22.9g{\cdot}m^{-2}{\cdot}d^{-1}$ and $0.28g{\cdot}g^{-1}{\cdot}d^{-1}$, respectively. These models can accurately estimate plant height, net photosynthesis rate, shoot fresh weight, and shoot dry weight of quinoa.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.4
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• pp.287-295
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• 2022

As low altitude long-range artillery threat has been strengthened, the development of anti-artillery interception system to protect assets against its attacks will be kicked off. We view the defense of long-range artillery attacks as a typical dynamic weapon target assignment (DWTA) problem. DWTA is a sequential decision process in which decision making under future uncertain attacks affects the subsequent decision processes and its results. These are typical characteristics of Markov decision process (MDP) model. We formulate the problem as a MDP model to examine the assignment policy for the defender. The proximity of the capital of South Korea to North Korea border limits the computation time for its solution to a few second. Within the allowed time interval, it is impossible to compute the exact optimal solution. We apply approximate dynamic programming (ADP) approach to check if ADP approach solve the MDP model within processing time limit. We employ Shoot-Shoot-Look policy as a baseline strategy and compare it with ADP approach for three scenarios. Simulation results show that ADP approach provide better solution than the baseline strategy.