• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.266-274
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• 2010

This study aim to investigate fundamentally the growth and physiological responses of tomato plants in responses to two different levels of water deficit, a weak drought stress (-25 kPa) and a severe drought stress (-100 kPa) in soil. The two levels of water deficit were maintained using a micro-irrigation system consisted of soil sensors for the real-time monitoring of soil water content and irrigation modules in a greenhouse experiment. Soil water contents were fluctuated throughout the 30 days treatment period but differed between the two treatments with the average -47 kPa in -25 kPa set treatment and the -119 kPa in -100 kPa set treatment. There were significant differences in plant height between the two different soil water statuses in plant height without differences of the number of nodes. The plants grown in the severe water-deficit treatment had greater accumulation of biomass than the plants in the weak water-deficit treatment. The severe water-deficit treatment (-119 kPa) also induced greater leaf area and leaf dry weight of the plants than the weak water-deficit treatment did, even though there was no difference in leaf area per unit dry weight. These results of growth parameters tested in this study indicate that the severe drought could cause an adaptation of tomato plants to the drought stress with the enhancement of biomass and leaf expansion without changes of leaf thickness. Greater relative water content of leaves and lower osmotic potential of sap expressed from turgid leaves were recorded in the severe water deficit treatment than in the weak water deficit treatment. This finding also postulated physiological adaptation to be better water status under drought stress. The drought imposition affected significantly on photosynthesis, water use efficiency and stomatal conductance of tomato plants. The severe water-deficit treatment increased PSII activities and water use efficiency, but decreased stomatal conductance than the weak water-deficit treatment. However, there were no differences between the two treatments in total photosynthetic capacity. Finally, there were no differences in the number and biomass of fruits. These results suggested that tomato plants have an ability to make adaptation to water deficit conditions through changes in leaf morphology, osmotic potentials, and water use efficiency as well as PSII activity. These adaptation responses should be considered in the screening of drought tolerance of tomato plants.

• Korean journal of applied entomology
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• v.19 no.3 s.44
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• pp.135-140
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• 1980

Out of 12 seed samples of Sesamum indicum L. tested, Macrophomina phaseolina (Tassi.) Goid was detected in 7 samples for the first time in Korea. Detailed descriptions of the habit character and pycnidial and pycnospore morphology of this fungus were described. Pycnidia of this fungus were not formed on agar media but they were formed on Water Agar Leaf Media under fluorescent light. M. phaseolina caused heavy reduction in seed germination and seedling stand of sesame and produced charcoal rot symptom on potato tubers. It was also detected from over wintered plant debris and diseased seedlings in the field.

• The Plant Pathology Journal
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• v.34 no.1
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• pp.59-64
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• 2018

Bacteriophages of Acidovorax citrulli, the causal agent of bacterial fruit blotch, were isolated from 39 watermelon, pumpkin, and cucumber leaf samples collected from various regions of Korea and tested against 18 A. citrulli strains. Among the six phages isolated, ACP17 forms the largest plaque, and exhibits the morphology of phages in the Myoviridae family with a head diameter of $100{\pm}5nm$ and tail length of $150{\pm}5nm$. ACP17 has eclipse and latent periods of $25{\pm}5min$ and $50{\pm}5min$, respectively, and a burst size of 120. The genome of ACP17 is 156,281 base pairs with a G + C content of 58.7%, 263 open reading frames, and 4 transfer RNA genes. Blast search and phylogenetic analysis of the major capsid protein showed that ACP17 has limited homology to two Stentrophomonas phages, suggesting that ACP17 is a new type of Myoviridae isolated from A. citrulli.

• Mycobiology
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• v.46 no.2
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• pp.172-176
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• 2018

A new species belonging to the genus Alternaria was isolated from the necrotic leaf spots of Brassica rapa subsp. pekinensis in Yuseong district, Daejeon, Korea. It is an occasional isolate, not an etiological agent, which is morphologically similar to A. broccoli-italicae, but differs in conidial size and conidiophore shape. Phylogenetic analysis using the sequence datasets of the internal transcribed spacer (ITS) region of the rDNA, glyceraldehyde-3-phosphate dehydrogenase (gpd), and plasma membrane ATPase genes showed that it is distantly related to A. broccoli-italicae and closely related to Alternaria species in the section Pseudoalternaria, which belonged to a clade basal to the section Infectoriae. Morphologically, the species is unique because it produces solitary conidia or conidial chains (two units), unlike the four members in the section Pseudoalternaria that produce conidia as short branched chains. It exhibits weak pathogenicity in the host plant. This report includes the description and illustration of A. brassicifolii as a new species.

• Korean Journal of Plant Taxonomy
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• v.34 no.1
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• pp.1-7
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• 2004

An unrecorded species in Korean flora, Hydrangea luteovenosa Koidz. (Hydrangeaceae) was collected from parasitic cone, Seongneol-orom region of Mt. Halla in Prov. Jeju-do. This species is readily distinguishable from H serrata (Thunb.) Ser. and H. petiolaris Siebold & Zucc. in Korea by habit, length and width of leaves, length of petiole, morphology of petals and leaf margins, position of ovary, number of stamens and secondary veins.

• Journal of Environmental Health Sciences
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• v.20 no.3
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• pp.85-95
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• 1994

This study was performed to find out the detoxication effects of natural products Thuja orientalis, leaf of acorn, aloe ferox mill, pine cone, pine root, lonicerae flos on nickel toxicity. The experimental rats were divided into 3 groups such as nickel alone treatment group, natural products treatment groups before and after nickel treatments. Each group was administered with difference dose of nickel such as 6.6 mg/kg/day, 13.2 mg/kg/day, 19.8 mg/kg/day respectively, for 14 days. Natural products were administered by 400 mg per kilogram body weight rat per day. The weight change of rats, nickel concentration in organs, survival rate of rats, morphology of organs were observed in the experimental groups. The results obtained by the experiment were as follows: 1. The rats in the group treated with natural products had no effect on the weight gain. 2. The mean survival rate of rats in the nickel alone treatment group was 72.5% (6.6 mg/kg/day), 68.9% (13.2 mg/kg/day), 60.2% (19.8 mg/kg/day) respectively. 3. As for the amount of nickel accumulation in organs, it was the lowest amount treated with pine cone, pine root in that order. 4. When kidney and liver tissues were observed with as optical microscope, obvious change were visible in those tissues treated groups with Lonicerae and Aloe.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.4
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• pp.422-426
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• 2009

Sweetpotato is one of the important starch crops, current more considered as an industrial crop rather than food because it has higher starch content (over 80% of biomass), it is used for bio resources for industrial area. In this study, we generated S598A (a mutant gene of oat phytochrome A) sweetpotato plant using Agrobacterium-transformation method. Morphological characteristics of S598A plant were compared with the wild type sweetpotato, S598A had darker green leaves, increased chlorophyll content higher than to two-fold, delayed leaf senescence, shorter plant height (60% shorter than that of the wild type), more number of leaves and petioles about 1.8-fold, shorter petiole length (30% shorter), 1.2-fold more branches and 1.6-fold thicker stem diameters. From this study, S598A plants with such phenotypic characteristics might be able to use the solar energy efficiently, to have increased tolerance to biotic and abiotic stresses and finally to increase productivity (not only starch yield but also root biomass yield). S598A sweetpotato lines are under field trials.

• BMB Reports
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• v.46 no.1
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• pp.31-36
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• 2013

Heat shock proteins play an important role in plant stress tolerance and are mainly regulated by heat shock transcription factors (Hsfs). In this study, we generated transgenic rice over-expressing OsHsfA7 and carried out morphological observation and stress tolerance assays. Transgenic plants exhibited less, shorter lateral roots and root hair. Under salt treatment, over-expressing OsHsfA7 rice showed alleviative appearance of damage symptoms and higher survival rate, leaf electrical conductivity and malondialdehyde content of transgenic plants were lower than those of wild type plants. Meanwhile, transgenic rice seedlings restored normal growth but wild type plants could not be rescued after drought and re-watering treatment. These findings indicate that over-expression of OsHsfA7 gene can increase tolerance to salt and drought stresses in rice seedlings.

• Research in Plant Disease
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• v.10 no.2
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• pp.130-134
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• 2004

The pathogenesity of 25 isolates of Colletotrichum gloeosporioides from apple, 42 isolates from pepper, 5 isolates from jujube, 8 isolates from persimmon was evaluated to know transmission to strawberry from other infected plants. Followings are the results. Colony morphology and spore size on potato dextrose agar was similar. When each isolate was inoculated on leaf and petiole of strawberry, isolates from persimmon was the most pathogenic. Five isolates, one pathogenic isolate per each host, were evaluated in simulated field condition under natural rainfall for their natural infectivity. All isolates infected strawberry in field condition, so C. gloeosporioides from other hosts are potential inoculum source of strawberry anthracnose.

• Korean Journal of Medicinal Crop Science
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• v.5 no.1
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• pp.28-35
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• 1997

Biosystematic study on Euphorbia ebracteolata Hayata was carried out by comparing ecology and morphology between wild and cultivated ones. As the result of this study, cultivation method about this medicinal plant was established, and ecologically, the shape of leaf or root of this plant appeared to be dependent on ecological environment while the hair of ovary and the involucel were considered to be fixed characters. From the investigation of natural conditions of habitats, this plant was considered to be a facultive sciofytes and a day neutral plant.