• Korean Journal Plant Pathology
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• v.1 no.3
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• pp.157-164
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• 1985

Some interactions in various soil conditions, numbers of microbial populations, root rot disease development and rates of spore germiation in three different location of soils were investigated. The calcium and magnesium contents were higher in replanted fields of ginseng (Panax ginseng) at Goesan. Potassium contents were high in replanted field at Poonggi and textural class of the soils was silt loam except for silt clay loam in first cultured field of ginseng at Goesan. For the germination process of Fusarium solani, F. moniliforme, F. oxysporum, and Alternaria panax, the percentage germination of fungal spores was high in double distilled water and Pfeffer's solution as media, whereas the lower rate of germination of spores was observed in soil extracts. Numbers of bacteria were high in replanted field soil at Gumsan, and propagules of fungi in replanted fields at Gumsan and Poonggi were higher than other soils, but higher numbers of actinomycetes were found in the first cultured field of ginseng at Goesan and Poonggi. Fungistasis was induced by higher microbial populations present in soil that was initiated when amended with garlic stalk, crushed bean and ginseng leaves. On the other hand, there was no fungistasis in soil amended with wheat and barley straw, and this tendency was a little difference on the soil sample.

• Korean Journal of Food Science and Technology
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• v.13 no.3
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• pp.209-218
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• 1981

Free fatty acid and total saponin, which were extracted from the spent media and colony of the strain Phizopus delemar Rh-1, were qualitatively examined by GLC and spectroscopic methods and compared with these of intact ginseng media. The 18, 18, and 14 free fatty acids were respectively identified from the control, spent media and colony. Among them, $iC_{12:0},\;C_{16:2},\;C_{17:0},\;C_{18:3}\; and\;C_{20:0}$ acids were not detectable from the colony. In add ition, $C_{16:2}\;and\;C_{20:0}$ peaks were rot found in the spent media and control, respectively. The isible absorption spectra of free fatty acids and total saponins in the control, spent media and colony were invariable. In contrast, however, the infrared and ultraviolet absorption spectra showed significant spectral variations, particularly in the it finger-print region, demonstrating that the ginseng components were considerably utilized by the strain Rhizopus delemar Rh-1.

• Horticultural Science & Technology
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• v.29 no.3
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• pp.273-277
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• 2011

Fusarium oxysporum f. sp. fragariae (Fof), the causal agent of crown and root rot in strawberry, is the most serious soilborne disease of nursery plants in Korea. The possibility of infection by Fof through runner propagation from infected mother plants of strawberry cv. 'Kumhyang' was assessed in stolons and daughter plants hanging from raised beds. The number of daughter plants from an infected mother plant in plastic house and photosynthetic photon flux (PPF) system, 280 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ was 2.7 and 3.8 plants after 58 days, respectively. However, healthy mother plants produced 6.5 and 8.4 daughter plants, respectively. The pathogen was detected in the uppermost portion of the stolon after 58 days, but was not detected further down the stolon. After 90 days, it was detected in all portions of the stolon between mother and $1^{st}$ daughter plant and in 60% of all $1^{st}$ daughter plants. The pathogen was not detected in the corresponding portions of the non-infected controls. These results show that infected mother plants can transmit Fof to their daughter plants without passing through the soil and $1^{st}$ daughter was used as mother plant in PPF system for propagating healthy plants.

• Korean journal of applied entomology
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• v.25 no.3 s.68
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• pp.169-173
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• 1986

Ginseng fields abolished by potato rot nematode (Ditylenchus destructor) (heavily infested with the nematode) were treated with selected nematicides after preplanting treatment with fumigants or non fumigant chemicals in the fall of 1982. Suppression of the nematode populations was noted in the fields fumigated by cylon (Cy) and treated with ethoprop (E) or triazophos (T). Also in these treatments, high percentages of shoot sprouting and low nematode damages were observed. In the fields fumigated by Cy, subsequent treatments with nonfumigant nematicides such as E, aldicarb (A), phenamiphos (Ph), oxamyl (O) and carbofuran (C) during cultivation had no effect on the significant decrease of the nematode, compared with Cy alone. No differences in shoot sprouting and symptom appearance were observed; however, survivalities of plants and root weights of 4-year old ginseng were high in A and E or E following preplanting treatment with E. Correlation coefficients of the nematode densities to host responses such as sprouting of shoots, symptom appearance, survivality of plants and weight of 4-year old ginseng roots were significant at and mostly before and after the time periods of survey.

• Journal of Ginseng Research
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• v.24 no.2
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• pp.53-57
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• 2000

Chlamydospores were isolated from hyphae of Cylindrocanon destmctans by homogenization and/or ultrasonic treatment. Rate of the isolated chlamydospores by the homogenization with glass tissue grinder were 9.8% of all total chlamydospores formed in the culture of C. destructans. The length of mycelial fragments after the homogenization was about 400㎛ They were, however, formed in clusters of the chlamydospores and the mycelia The rate of the isolated chlamydospores from additional ultrasonic treatment after the homogenization of the mycelia were 74.3%. The length of mycelial fragments with the ultrasonic treatment was about 20 fm and chlamydospores seemed to be isolated from the mycelial mats and dispersed evenly in the culture. The numbers of chlamydospore in a catena were 1 to 8 cells after the homogenization on potato dextrose agar (PDA). Meanwhile the numbers of them after added ultrasonic treatment were 1 to 4 cells. Germination percentages of the isolated chlamydospores from the ultrasonic treatment were 46.8% after incubation of 2 days on PDA at 20。C and 60.7% after incubation of 13 days at 5。C, respectively. Germination rate of chlamydospores to the total chlamydospores produced by the ultrasonic treatment was 55.8%. However, it was increased to 74% when it was measured in the germinated catenae to the total catenae.

• The Korean Journal of Mycology
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• v.44 no.3
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• pp.196-200
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• 2016

Symptoms of summer patch were observed on Kentucky bluegrass (Poa pratensis L.) cv. "Midnight II" from mid-June in 2015 in Seoul, Korea. The symptoms appeared as leaf blight, root rot, and frog-eye patch, which are typical of summer patch. To identify the causal agent of these symptoms, a pathogen was isolated from diseased leaves and roots, and the cultural, morphological, and phylogenetic characteristics were analyzed. The isolate reached 50-60 mm on potato dextrose agar (PDA) after 10 days as a white-grey mycelium with septa, and became olive-green or brown from the center. Phialide-like structures were observed at the ends of hyphae, and conidia were rarely observed. A phylogenetic analysis was conducted based on large subunit (LSU) and RNA polymerase II large subunit (RPB1) sequences. According to this analysis, the isolated pathogen was confirmed to be Magnaporthiopsis poae. In a pathogenicity test, summer patch symptoms were observed at 20 days after inoculation using the same grass cultivar. This is the first report of summer patch disease caused by M. poae on cool season grass in Korea.

• Korean Journal of Microbiology
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• v.42 no.2
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• pp.135-141
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• 2006

We isolated a bacterium which produces antifungal substances from the Sanktpeterburg soils at Russia. The iso-lated strain was identified as Brevibacillus sp. and shown a strong antifungal activity on plant pathogenic fungi. Brevibacillus sp. KMU-391 produced maximum level of antifungal substances under incubation aerobically at $30^{\circ}C$ for 48 hours in trypticase soybean broth containing 1.0% sucrose and 1.0% polypeptone at 180 rpm and initiated pH adjusted to 7.0. Precipitate of culture broth by $30{\sim}60%$ ammonium sulfate precipitation exhibited strong antifungal activity against Didymella bryoniae by dry cell weight. Butanol extract of cultured broth also shown fungal growth inhibitory activity against Botrytis cinerea KACC 40573, Botrytis fabae KACC 40962, Colletotrichum gloeosporioides KACC 40804, Colletotrichum orbiculare KACC 40808, Didymella bryoniae KACC 40669, Fusarium graminearum KACC 41040, Fusarium oxysporum KACC 40037, Fusarium oxysporum KACC 40052, Fusarium oxysporum f, sp. radicis-Iycopersici KACC 40537, Fusarium oxysporum KACC 40902, Monosporascus cannonballus KACC 40940, Phytophthora camvibora KACC 40160, Rhizoctonia solani AG-1(IA) KACC 40101, Rhizoctonia solani AG-4 KACC 40142, and Scleotinia scleotiorum KACC 41065 by agar diffusion method.

• Journal of Life Science
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• v.12 no.3
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• pp.264-273
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• 2002

We have isolated and artificially expressed three cDNA clones of Capsicum annuum PR5 genes for elucidating the antifungal activity against Phytophthora capsici which contracted a hot pepper root rot in field condition. Three divergent PR5 proteins from hot pepper were designated as CAPR5-1 and CAPR5-2 from susceptible cultivar (Subicho) as well as CAPR5-3 from resistant cultivar (CM331) in response to P. capsici. The cDNA similarity was found over 80% of identity among the three CAPR5s, and deduced amino acid sequence was characterized that all of CAPR5s contained 16 cysteine residues which possibly had a significant role in the structural formation. The result of genomic DNA blot showed that CAPR5-1 and CAPR5-2 existed as single copy in the Subicho genome. Three recombinant CPARs in E. coli were identified by SDS-PACE, and each expressed protein was treated on the PDA medium which contained cultured pathogens. Although three CAPR5 proteins did not affected the hyphal growth of Glomerella glycines and Colletotrichum fagenarium, CAPR5-1, CAPR5-2, and CAPR5-3 showed a specific antifungal activities against P. capsici.

• Korean Journal of Breeding Science
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• v.41 no.2
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• pp.158-162
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• 2009

"Wonkwang" is a new sprout-soybean cultivar developed from the cross between Danyeobkong and MS91001 at the Honam Agricultural Research Institute (HARI) and National Institute of Crop Science (NICS), RDA, in 2007. The preliminary, advanced and regional yield trials to evaluate the performance of Iksan 56 were carried out from 2003 to 2007. This cultivar has a determinate growth habit, purple flower, grayish brown pubescence, yellow seed coat, Grayish brown hilum, lanceolate leaflet shape and small seed size (10.9 g/100 seeds). The maturity date of "Wonkwang" is three days later than the check variety, "Pungsan". It has a good seed quality for soybean-sprout and resistance to lodging. The soybean-sprouts grown from "Wonkwang" have high isoflavone ($3,481{\mu}g/g$)contents. This cultivar has resistance to soybean mosaic virus (SMV) and necrotic symptom (SMV-N) and other most troublesome soybean diseases which are bacterial pustule and black root rot. The grain yield of "Wonkwang"in the regional yield trials (RYT) for 3 consecutive years was averaged 3.05 ton per hectare, which was 8% higher than that of the check cultivar "Pungsan".

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.202-202
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• 2022

Recently days, soybean production in paddy field is increasing, from 4,422 ha in 2016 to 10,658 ha in 2021 in Korea. It is easy for Phytophthora stem and root rot (PSR) occurring in paddy field condition, when it is poorly drained soils with a high clay content, and temporary flooding and ponding. Therefore PSR resistant soybean cultivar is required. The objective of this study is to identify QTL region and candidate genes relating to PSR resistance of the race in main soybean cultivation area in Korea. 210 soybean materials including cultivars and germplasm were used for inoculation and genome-wide association study (GWAS). Inoculation was conducted using stem-scar method with 2 replications in 2-year for the race 3053 from Kimje and 3617 from Andong. 210 materials were genotyped with Soya SNP 180K chip, and structure analysis and association mapping were conducted with QTLMAX V2. The results of inoculation showed that survival ratio ranged from 0% to 96.7% and mean 9.7% for 3053 and ranged from 0% to 100% and mean 7.6% for 3617. Structure analysis showed linkage disequillibrium (LD) was decayed below r²=0.5 at 335kb of SNP distance. Significant SNPs (LOD>7.0) were identified in Chr 1, 2, 3, 4, 5, 11, 14, 15 for 3053 and Chr 1, 2, 3, 7, 10, 14 for 3617. Especially, LD blocks (AX-90455181;15,056,628bp~AX-90475572;15,298,872bp) in Chr 2 for 3053 and 3067 were duplicated. 29 genes were identified on these genetic regions including Glyma.02gl47000 relating to ribosome recycling factor and defense response to fungus in Soybase.