• Research in Plant Disease
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• v.22 no.1
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• pp.1-8
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• 2016

Elsinoe fawcettii causing citrus scab was suppressed by rhizobacterial strains such as Burkholderia gladioli MRL408-3, TRH423-3 and Pseudomonas fluorescens THJ609-3, TRH415-2 having antifungal activity. The leaf surface of Satsuma mandarin, which was pre-treated with the rhizobacterial strains, was observed by a scanning electron microscope (SEM) after inoculation with E. fawcettii. The number of lesions was reduced on the leaves pre-treated with the rhizobacterial strains compared to those of untreated leaves. Especially, the lesions numbers was apparently reduced on the leaves pre-treated with B. gladioli MRL408-3. The observation by SEM revealed that not only the germination rate but also the length of germ tube of the pathogen were decreased on the rhizobacterial strains pre-treated leaves. These inhibition of the fungal growth was more strongly expressed on the leaves pre-treated with commercial fungicide imibenconazole, by which the lesions was rarely found on the leaves. Based on these results, it was suggested that rhizobacterial strains may inhibit the germination and growth of the E. fawcettii on the surface of citrus leaves, resulting in decrease of disease severity.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.366-374
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• 2014

The study was conducted to investigate the possibility that epigenetic DNA methylation causes tree phenotypic variation in autotetraploids through evaluating the phenotypic variation and DNA methylation in autotetraploids occurred spontaneously from diploid trifoliate orange. Chromosome analysis confirmed that fourteen trifoliate orange trees of selected by flow cytometry were tetraploids (2n = 4X = 36) without any aneuploids. Chromomycin A3 staining determined that these trees were all autotetraploid with doubled chromosome set. Tree phenotypes, such as tree height and width, branching number, length, and angle, internode length, and leaf characteristics, varied in the autotetraploids. Chlorophyll indices were diverse in the autotetraploids, but photosynthetic rates were not significantly different. In addition, a wide range of variation was observed in stomatal density and guard cell length. Analysis of global cytosine DNA methylation showed that there was a variation of the methylation level in autotetraploids. More than half of 14 autotetraploids had at least 2 times higher methylation level than diploid trifoliate orange. The results indicate that tree phenotypic variation in autotetraploids might be related to global DNA methylation for reducing gene redundancy.

• Food Science and Preservation
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• v.24 no.6
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• pp.842-848
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• 2017

Hylotelephium erythrostictum is commonly used as a medicinal herb. In this study, H. erythrostictum leaf (HEL), branch (HEB), root (HER), and above ground (HEAG) extracts were evaluated for their antioxidant properties. The antioxidant activities were assayed by three methods based on scavenging of DPPH, ABTS and superoxide anion radical. HEAG extract showed the highest DPPH, ABTS, superoxide anion radical scavenging activities. HEAG extract also exhibited the highest phenolic content (230 mg/g gallic acid equivalent). In our research for anti-inflammatory ingredients, the extract of HEAG inhibited the generation of nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. To test the inhibitory effects of HEAG on pro-inflammatory cytokines, we conducted ELISA assay for the measuring the generation of tumor necrosis factor $(TNF)-{\alpha}$, IL (interleukin)-$1{\beta}$, and IL(interleukin)-6 in LPS-stimulated RAW264.7 macrophage cells. In these assays, HEAG ethanol extract showed a dose-dependent decrease in the production of $TNF-{\alpha}$, $IL-1{\beta}$, and IL-6. Based on these results, extract of HEAG could be the efficient candidate for anti-inflammatory agents.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.85-85
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• 2003

This study has been undertaken to increase availability of native camellia in Jeonnam as a medicinal resource and to isolate the effective components from them. Multidrug resistance(MDR) by tumor cells is a major obstacle to successful cancer chemotherapy. We report that the crude extracts of camellia flowers, leaves has a chemosensitizing effect that can reverse Pgp-mediated MDR by increasing the intracellular accumulation of drugs. The cytotoxic and chemosensitizing effects of MeOH extract from 12 spp. citrus fruits on the AML-2/D100 were determined using MTT assay. Chemosensitizing effects was screened in the presence of vincristine, a good substrate of Pgp. IC$\sub$50/ for extracts in AML-2/WT was found to be 65∼350$\mu\textrm{g}$/$m\ell$ whereas the range of its mean IC$\sub$50/ value in Pgp-overexpressing cells (AML-2/Dl00) in the presence of vincristine was 90∼400$\mu\textrm{g}$/$m\ell$. Of the extracts tested, mature leaf extract displayed the most potent chemosensitizing effect［IC$\sub$50/;100 $\mu\textrm{g}$/$m\ell$, CR;1.06, RF;2.97 in the presence of VCR］. This indicates that the toxicity (IC$\sub$50/;288.89$\mu\textrm{g}$/$m\ell$) of mature leaf extract is minimal at concentrations required for a complete reversal of the drug resistance. Also, this result indicates that crude extracts of camellia mature leaves would contain some principles which have chemosensitizing activity.

• Research in Plant Disease
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• v.11 no.1
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• pp.10-15
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• 2005

The occurrence of melanose was investigated on yuzu at Goheung and Boseong in Jeonnam province in 1997 and 1998 seasons. The disease occurrence on leaf was initiated from late May in 1997 and early May in 1998, severest in late of June on leaf, and in case of fruit, initiated from early July in 1997 and late June in 1998 with a peak in early August. The disease was occurred in twenty days more earlier in 1998 season than 1997 season. We think this was caused by temperatures during April and May. And it was supposed that the disease severity on the severest late of June was closely related to the rainfall and relative humidity during June. The disease severity was severer in old tree than the young.

• Journal of Bio-Environment Control
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• v.20 no.3
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• pp.204-210
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• 2011

This experiment was conducted to investigate the effect of water states (water, osmotic potential and turgor pressure) of fruit vesicle and leaf on soluble solids and organic acid contents of fruits of 'Shiranuhi' mandarin hybrid, M16 A line during the fruit maturing season in plastic house cultivation. The 'Shirauhi' grafted on 'Swingle citrumelo', strong strength of rootstock, produced fruit with lower soluble solids and organic acid content than 'Trifoliate' orange rootstock. The fruits vesicle water potential and turgor pressure measured before dawn in 'Swingle citrumelo' were higher tendency than the 'Trifoliate' orange, but osmotic potential values were lower than the 'Trifoliate' orange. The changes of leaf water potential were very similar to the fruit. The results suggest that in the 'Shirauhi' fruits grafted on two rootstocks changes of soluble solids and organic acid content of the fruit were influenced by the leaf water potential and the osmotic potential of the fruit vesicles, which might be caused by the difference of root distribution between two rootstocks.

• Korean Journal of Pharmacognosy
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• v.42 no.2
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• pp.187-194
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• 2011

Aldose reductase (AR), the key enzyme in the polyol pathway, plays an important role in the development of the diabetic complications. None of Aldose reductase Inhibitor (ARI) has achieved worldwide use because of limited efficacy or undesirable side effects. Therefore, evaluating natural sources for ARI potential may lead to the development of safer and more effective agents against diabetic complications. Fifty two Chinese herbal medicines have been investigated for inhibitory activities on AR. Among them, twelve herbal medicines, Artemisia anomala (aerial part), Centella asiatica (aerial part), Scutellaria baicalensis (root), Senecio chrysanthermoides (whole plant), Gleditsia japonica (twig), Zizyphus jujube (twig, leaf), Citrus aurantium (fruit), Hydnocarpus anthelmintica (fruit), Potaninia mongolica (aerial part), Tribulus terrestris (fruit), Artemisia apiacea (aerial part) and Eclipta prostrate (aerial part) exhibited a significant inhibitory activity against AR. Particularly, Artemisia anomala, Centella asiatica and Scutellaria baicalensis showed four times more potent inhibitory activity than the positive control, 3,3-tetramethyleneglutaric acid (TMG).

• Journal of Bio-Environment Control
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• v.25 no.1
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• pp.57-62
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• 2016

This study was conducted to find out the influence of red LED (Light Emitting Diode) lighting on the photosynthesis, vegetative growth and fruit quality of 'Fuji'/M.26 adult apple tree during night after sunset. The photosynthetic rate, stomatal conductance and transpiration rate at daytime of red LED treatments was not different to those of the control. However, the stomatal conductance and transpiration rate at the nighttime of red LED treatments were lower than those of the control, and the red LED lighting during night after sunset was not induce to photosynthesize at nighttime. In the leaf characteristics, the red LED lighting seemed to increase leaf area and C/N ratio, but decrease SPAD value. The bourse shoot length of the red LED treatments was shorter than that of the control. In the fruit quality, the red LED lighting seemed to increase ethylene production, respiration rate, soluble solid content and fruit red color, and especially the fruit red color tend to increase as the red LED lighting time was longer. In conclusion, the red LED lighting during night after sunset of 'Fuji'/M.26 apple tree promoted the fruit maturation.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.3
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• pp.262-276
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• 2018

Models to predict Leaf Wetness Duration (LWD) were evaluated using the observed meteorological and dew data at the 11 citrus orchards in Jeju, South Korea from 2016 to 2017. The sensitivity and the prediction accuracy were evaluated with four models (i.e., Number of Hours of Relative Humidity (NHRH), Classification And Regression Tree/Stepwise Linear Discriminant (CART/SLD), Penman-Monteith (PM), Deep-learning Neural Network (DNN)). The sensitivity of models was evaluated with rainfall and seasonal changes. When the data in rainy days were excluded from the whole data set, the LWD models had smaller average error (Root Mean Square Error (RMSE) about 1.5hours). The seasonal error of the DNN model had the similar magnitude (RMSE about 3 hours) among all seasons excluding winter. The other models had the greatest error in summer (RMSE about 9.6 hours) and the lowest error in winter (RMSE about 3.3 hours). These models were also evaluated by the statistical error analysis method and the regression analysis method of mean squared deviation. The DNN model had the best performance by statistical error whereas the CART/SLD model had the worst prediction accuracy. The Mean Square Deviation (MSD) is a method of analyzing the linearity of a model with three components: squared bias (SB), nonunity slope (NU), and lack of correlation (LC). Better model performance was determined by lower SB and LC and higher NU. The results of MSD analysis indicated that the DNN model would provide the best performance and followed by the PM, the NHRH and the CART/SLD in order. This result suggested that the machine learning model would be useful to improve the accuracy of agricultural information using meteorological data.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.18-25
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• 2014

This study was conducted to investigated effects of water relation of mulching and trickle irrigation on the external and internal fruit quality in Satsuma mandarin grafted on trifoliate orange rootstock in a orchard assigned to randomly three groups; whole period of Tyvex mulching (TM), Tyvex mulching with trickle irrigation once a week from October 22 to harvesting season (WM) and non-mulching treatment (NM). The average soil moisture content in the TM was lower than the WM during the time of trickle irrigation from Oct. 21 to Nov. 28. The leaf water potential was at the level of ${\Psi}max$ of -1.5 to -2.5 MPa during whole period of Tyvex mulching treatment but gradually increased at the point of supplement of water. The water and osmotic potential in juice vesicle was decreased by drought but increased again in response to the supply of water in WM. The total soluble solids (TSS) in fruit juice was increased by drought stress, but diminished in response to supply of water after drought. The content of titratible acidity was increased by drought stress but gradually decreased due to supplement of water after drought, reached it at the level of 1%. It was suggested that the accumulation of the total soluble solids compensates the degree of active osmoregulation and the decrease in content of acidity accounts for the fast respiration and water uptake resulted of the water after drought.