• The Plant Pathology Journal
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• 제21권1호
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• pp.83-85
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• 2005

Ditylenchus acris was isolated from diseased strawberry plants. Frequently, D. acris and Aphelenchoides fragariae occur together in a strawberry plant. Both species appeared very similar in the shape, length, swimming behavior and causing symptoms, and difficult to distinguish them by a stereomicroscope. But they were easily distinguished under a compound microscope especially by their tail shape, median bulb, vulva position, and bursa.

• The Plant Pathology Journal
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• 제36권4호
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• pp.305-313
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• 2020

Host shifting and host expansion of fungal plant pathogens increases the rate of emergence of new pathogens and the incidence of disease in various crops, which threaten global food security. Magnaporthe species cause serious disease in rice, namely rice blast disease, as well as in many alternative hosts, including wheat, barley, and millet. A severe outbreak of wheat blast due to Magnaporthe oryzae occurred recently in Bangladesh, after the fungus was introduced from South America, causing great loss of yield. This outbreak of wheat blast is of growing concern, because it might spread to adjacent wheat-producing areas. Therefore, it is important to understand the host range and population structure of M. oryzae and related species for determining the evolutionary relationships among Magnaporthe species and for managing blast disease in the field. Here, we collected isolates of M. oryzae and related species from various Poaceae species, including crops and weeds surrounding rice fields, in Korea and determined their phylogenetic relationships and host species specificity. Internal transcribed spacer-mediated phylogenetic analysis revealed that M. oryzae and related species are classified into four groups primarily including isolates from rice, crabgrass, millet and tall fescue. Based on pathogenicity assays, M. oryzae and related species can infect different Poaceae hosts and move among hosts, suggesting the potential for host shifting and host expansion in nature. These results provide important information on the diversification of M. oryzae and related species with a broad range of Poaceae as hosts in crop fields.

• 한국환경농학회지
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• 제37권3호
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• pp.160-165
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• 2018

BACKGROUND: Mixed cropping of legume and grass was effective system in view point of providing organic matter and nitrogen or reducing the nitrogen starvation of following crop. The relation of the change of N and P constituents depending on the cropping types and those effects on the growth and nutrient uptake of the following crop were observed. METHODS AND RESULTS: Three cropping types, hairy vetch mono cropping, barley mono cropping, and mixed cropping of hairy vetch and barley were applied. Soil properties, growth characteristics, and nitrogen production of green manure crops were observed. In additions, the effect of cropping types on the growth pattern of corn as the following crop was observed. In the mixed cropping system, creeping type hairy vetch climbed to the erect type barely for light utilization resulting in improvement of light interception rate and higher LAI (Leaf Area Index) than in mono cropping. Mixed cropping showed higher biomass production and soil nitrogen availability among the cropping types, indicating relatively much more nutrient supply and higher yield production of following crop. CONCLUSION: Mixed cropping showed relatively higher LAI (dry matter) mainly because of intense competition for light utilization usually after flowering stage. Mixed cropping also showed relatively higher yield of corn, the following crop rather than other types, mainly due to the more biomass production potential and higher N and P production ability. Therefore, mixed cropping was adaptable method to reduce or replace chemical fertilizer application for environmentally-friendly agriculture.

• Mycobiology
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• 제38권1호
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• pp.74-77
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• 2010

To obtain basic information on the detection of cellulolytic activity in Auricularia auricula-judae, the influences of dye reagent, pH, and temperature were assessed. Chromogenic dye (congo red, phenol red, remazol brilliant blue, and trypan blue) was individually incorporated into a medium containing either carboxymethyl-cellulose, Avicel, or D-cellobiose as a polysaccharide carbon substrate. The other assessments utilized pHs ranging from 4.5 to 8.0 and temperatures from $15\sim35^{\circ}C$. Overall, when A. auricula-judae species were transferred onto media contained Congo red and adjusted pH 7.0 and then incubated at $25^{\circ}C$ for 5 days, the clear zone indicative of cellulolytic activity was more pronounced.

• 식물병연구
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• 제22권3호
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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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• 제43권3호
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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.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2002년도 총회 및 추계학술발표회
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• pp.70.3-71
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• 2002

• Mycobiology
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• 제46권3호
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• pp.283-286
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• 2018

Fusarium graminearum causes the devastating plant disease Fusarium head blight and produces mycotoxins on small cultivated grains. To investigate the timeframe of F. graminearum infection during rice cultivation, a spore suspension of F. graminearum was applied to the rice cultivars Dongjin 1 and Nampyeongbyeo before and after the heading stage. The disease incidence rate was the highest (50%) directly after heading, when the greatest number of flowers were present, while only 10% of the rice infected 30 days after heading showed symptoms. To understand the mechanism of infection, an F. graminearum strain expressing green fluorescent protein (GFP) was inoculated, and the resulting infections were visually examined. Spores were found in all areas between the glume and inner seed, with the largest amount of GFP detected in the aleurone layer. When the inner part of the rice seed was infected, the pathogen was mainly observed in the embryo. These results suggest that F. graminearum migrates from the anthers to the ovaries and into the seeds during the flowering stage of rice. This study will contribute to uncovering the infection process of this pathogen in rice.

• 한국환경농학회지
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• 제39권4호
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• pp.312-318
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• 2020

BACKGROUND: Photoreversibility, a reversion of the inductive effect of a brief red light pulse by a subsequent far red light pulse, is a property of photo responses regulated by the plant photoreceptor phytochrome B. Plants use photoreceptors to sense photo signal and to adapt and modify their morphological and physiological properties. Phytochrome recognizes red light and far red light and plays an important role in regulating plant growth and development. METHODS AND RESULTS: The reversal responses of growth and fruiting characteristics were investigated to increase the yield of oriental melon (Cucumis Melo L. var. Kumsargakieuncheon) by means of controlling light quality in a plastic house. Red (R:660nm) and far red (FR:730nm) lights were subsequently irradiated on the whole stems and leaves of the oriental melon plant during growing periods, using red and far red LEDs as light sources, from 9:00 PM daily for 15 minutes. The intensities of R and FR light were 0.322-0.430 μmol m-2s-1 and 0.250-0.366 μmol m-2s-1, respectively. Compared to R light irradiation, combination of R and FR light irradiation increased the length of internode, number of axillary stems, number of female flowers, and fruit number of oriental melons. The results of treatment with R were similar to R-FR-R light irradiation in terms of length of internode, number of axillary stems, number of female flowers, and number of fruits. When FR treatment was considered, R-FR and R-FR-R-FR light irradiation had similarities in responses. These reversal responses revealed that oriental melon showed a photoreversibility of growth characteristics, flowering, and fruiting. CONCLUSION: These results suggested the possibility of phytochrome regulation of female flower formation and fruiting in oriental melon. The fruit weight of the oriental melon was the heaviest with the R light irradiation, while the number of fruits was the highest with the FR light. With the FR light irradiation, the fruit weight was not significantly higher compared to that of the control. Meanwhile, the yield of oriental melon fruits increased by 28-36% according to the intensities of the FR light due to the increases of the number of fruits.

• Food Science and Biotechnology
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• 제17권1호
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• pp.135-143
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• 2008

The ratio between 11S Sand 7S globulins was greater in large seed size varieties (LSSVs) of soybean than in small seed size varieties (SSSVs) or medium seed size varieties (MSSVs) but did not differ between MSSVs and SSSVs. The cysteine and methionine contents of 11S globulins were greater than those of total seed proteins and 7S globulins. The acidic monoamino monocarboxylic amino acids were the most abundant class of amino acid in soybean seed (27.2%) and soybean curd protein (29.3%). Isolated 7S and 11S fractions were analyzed by HPLC. Of the 12 peaks detected, 4 constituted 64.1% of the proteins of the SSSVs, 65.6% of the proteins of the MSSVs, and 70.5% of the proteins of the LSSVs. The 11S/7S globulin ratio was related to the yield and hardness of soybean curd. The MSSVs had the greatest yield of soybean curd, but the soybean curd hardness of the MSSVs was greater than that of the SSSVs. These results show that the 11S/7S ratio and color of soybean seeds can be used to predict the yield, hardness, and color of soybean curd.