• 한국약용작물학회:학술대회논문집
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• 2012.05a
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• pp.273-274
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• 2012

• Research in Plant Disease
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• v.21 no.1
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• pp.24-26
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• 2015

In April 2014, seedlings of Fallopia multiflora showing wilt symptom were first found at a greenhouse in Punggi-eup, Yeongju-si, Korea. A Fusarium-like fungus was isolated from the wilted plant and it was identified as Fusarium oxysporum based on morphological characteristics and nucleotide sequence data of translation elongation factor 1-${\alpha}$. The fungus isolated from the diseased plant was revealed to be pathogenic to the host plant through pathogenicity tests, and the reisolation of the pathogen confirmed Koch's postulates. This is the first report of Fusarium wilt occurring on Fallopia multiflora in the world.

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.421-430
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• 2022

Crop load management in apple trees is important for achieving optimum productivity and crop value. Hence, we investigated the influence of different crop loads on the fruit quality, mineral content, and yield of the 'RubyS' apple variety. After 4 weeks of full bloom, the crop load was adjusted by hand thinning to different (5, 10, and 15 fruits·cm^-2) trunk cross-sectional areas (TCSA), representing low, medium, and high crop loads. The low crop load increased the fruit size and weight, the development of the red-blushed area, and the peel color a^* at harvest; however, it reduced the total number of fruits·tree^-1 and yield compared with that of the other crop loads. The medium crop load improved the fruit weight, flesh firmness, and soluble solids content and reduced the fruits·tree^-1 but did not affect the fruit size and yield. However, there were no significant differences in the titratable acidity and starch index among the crop loads. The fruit mineral content (phosphorus and potassium) was higher in the low and medium crop loads compared to the high crop load. However, the nitrogen, calcium, and magnesium contents in the fruits were not affected by the crop loads. Overall, this study suggests that a low crop load improves the fruit size and weight, but its effect on the quality and fruit mineral content is similar to that of a medium crop load. Therefore, the optimum crop load level for the 'RubyS' apple trees was approximately 10 fruits·cm^-2 TCSA.

• Korean Journal of Plant Resources
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• v.27 no.6
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• pp.601-609
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• 2014

In this study, the effect of plant extract on the senescence action and cell survival rate in two types of cells, in which aging was derived by adriamycin, was analyzed to find the materials for suppressing cell senescence from natural resources. The results are as follows. For human umbilical vein endothelial cells (HUVECs), the fruit of Physalis angulata L. and the aerial part of Synurus deltoides (Aiton) Nakai showed excellent cell-senescence inhibition activities in a treatment concentration-dependent manner, demonstrating the high possibility for utilization as a material for prevention and treatment for vascular diseases. The water extract from the root of Polygonatum odoratum var. pluriflorum for variegatum Y. N. Lee showed potent cell-senescence inhibitory effect for human dermal fibroblasts (HDFs). Thus it is considered that the additional study on the plant needs for elucidating the possible utilization as material for skin health improvement.

• Journal of Microbiology and Biotechnology
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• v.31 no.11
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• pp.1576-1582
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• 2021

Bacterial β-glucuronidase in the intestine is involved in the conversion of 7-ethyl-10-hydroxycamptochecin glucuronide (derived from irinotecan) to 7-ethyl-10-hydroxycamptothecin, which causes intestinal bleeding and diarrhea (side effects of anti-cancer drugs). Twelve compounds (1-12) from Polygala tenuifolia were evaluated in terms of β-glucuronidase inhibition in vitro. 4-O-Benzoyl-3'-O-(O-methylsinapoyl) sucrose (C3) was highly inhibitory at low concentrations. C3 (an uncompetitive inhibitor) exhibited a k_i value of 13.4 μM; inhibitory activity increased as the substrate concentration rose. Molecular simulation revealed that C3 bound principally to the Gln158-Tyr160 enzyme loop. Thus, C3 will serve as a lead compound for development of new β-glucuronidase inhibitors.

• Research in Plant Disease
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• v.22 no.3
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• pp.190-193
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• 2016

In 2010 and 2012, damping-off symptoms were found on melon seedlings grown in Yeongam and Suncheon, Korea. Water-soaked and discolored lesions appeared on the lower stems of the infected plants. The diseased plants became wilted and stunted, and eventually collapsed. On the basis of morphological characteristics and molecular analyses of internal transcribed spacer (ITS) rDNA and cytochrome oxidase II (cox2) sequences, the causal organism was identified as Pythium spinosum. The isolates were pathogenic to melon under pot conditions. To our knowledge, this is the first report of P. spinosum causing damping-off on melon in Korea.

• Mycobiology
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• v.43 no.3
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• pp.343-346
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• 2015

In 2006~2010, leaf spot symptoms, that is, small, yellow spots that turned into dark brown-to-black lesions surrounded by a yellow halo, were observed on Cymbidium spp. in Gongju, Taean, and Gapyeong in Korea. A Fusarium species was continuously isolated from symptomatic leaves; in pathogenicity testing, isolates caused leaf spot symptoms consisting of sunken, dark brown lesions similar to the original ones. The causal pathogen was identified as Fusarium subglutinans based on morphological and translation elongation factor 1-alpha sequence analyses. This is the first report of F. subglutinans as the cause of leaf spot disease in Cymbidium spp. in Korea.

• Research in Plant Disease
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• v.20 no.4
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• pp.264-269
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• 2014

The effect of biological control of the root-knot nematode, Meloidogyne incognita, on cucumber and lettuce was evaluated with green manure crop species in greenhouse. Nematicidal effect of sudan grass cultivation in cucumber greenhouse was comparable to that of chemical treatment with fosthiazate GR, showing the high activity of 88.6%. Sudan grass cultivation in lettuce greenhouse significantly reduced the number of M. incognita in soil, showing 93.5% of nematiidal activity. In addition, since growth of sudan grass was superior to other green manure crop species, it is considered that cultivation of sudan grass is proper to control M. incognita in greenhouse.

• Research in Plant Disease
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• v.16 no.3
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• pp.290-293
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• 2010

Bacterial canker, caused by Clavibacter michiganensis subsp. michiganensis, is a very damaging disease to tomato (Lycopersicon esculentum) farm in Korea. It infects tomato, spreads through the xylem and causes bacterial wilt and canker. Selection of resistant cultivar is the best way to prevent or reduce the occurrence of the disease. Thirty-nine tomato cultivars, twenty-one cherry tomato cultivars and thirteen rootstock tomato cultivars were inoculated with Clavibacter michiganensis subsp. michiganensis, to evaluate tomato cultivarspecific resistance against bacterial canker. In the evaluation of 73 major commercial cultivars, 'Sunmyung', 'Sweet', 'Akiko', 'Dadaki', 'Match', 'Magnet', 'Friend', and 'Greenpower' were found to have a high level of resistance to bacterial canker of tomatoes.

• Korean Journal of Plant Resources
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• v.28 no.6
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• pp.718-726
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• 2015

In this study, the inhibitory activities of fifty plant extracts on IgE-mediated degranulation in the rat basophilic leukemia cell line (RBL-2H3 cells) were measured; the release of interleukin (IL)-4 and β-hexosaminidase from IgE-sensitized cells treated with the plant extracts was measured; and the effects of the plant extracts on cell viability were tested. The results of the analysis of plant extracts at 20 μg/ml, including the aerial part of Magnolia sieboldii K. Koch, exhibited suppressive activities upon the release of IL-4. Furthermore, several plant extracts including methanol extracted from Lindera erythrocarpa Makino (aerial part) at the same concentration significantly inhibited the release of β-hexosaminidase. Twenty-six of the plant extracts, including methanol extract of Weigela subsessilis (Nakai) L. H. Bailey (branch), showed a cell proliferation effect of over 80% at 100 μg/ml. In conclusion, the results suggest that the leaf/stem of Geum japonicum Thunb. and the stamen/ovary of Nelumbo nucifera Gaertn., which exhibited effective inhibition on β-hexosaminidase release and IL-4 release from mast cells and showed high cell viability, could be useful candidates as anti-allergy materials.