• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.320-320
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• 2000

• Research in Plant Disease
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• v.21 no.4
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• pp.326-329
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• 2015

Fusaric acid is a mycotoxin produced by species of the fungus Fusarium and can act synergistically with other Fusarium toxins. In order to develop a specific detection method for fusaric acid-producing fungus, PCR primers were designed to amplify FUB10, a transcription factor gene in fusaric acid biosynthetic gene cluster. When PCR with Fub10-f and Fub10-r was performed, a single band (~550 bp) was amplified from F. oxysporum, F. proliferatum, F. verticillioides, F. anthophilum, F. bulbicola, F. circinatum, F. fujikuroi, F. redolens, F. sacchari, F. subglutinans, and F. thapsinum, all of which were known for fusaric acid production. Whereas the FUB10 specific band was not amplified from Fusarium species known to be trichothecene producer. Because production of fusaric acid can co-occur in species that also produce fumonisin mycotoxins, we developed a multiplex PCR assay using the FUB10 primers as well as primers for the fumonisin biosynthetic gene FUM1. The assay yielded amplicons from fumonisin producers such as F. proliferatum and F. verticillioides, allowing for the simultaneous detection of species with the genetic potential to produce both types of mycotoxins.

• Korean Journal of Animal Reproduction
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• v.20 no.3
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• pp.299-305
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• 1996

This study was conducted to investigate the effects of co-culture for the development rate to morula/blastocyst stages of early porcine embryos, derived from oocytes matured and fertilized in vitro, with porcine oviductal epithelial cell monolayers(POEC) in the two different media, respectively. The rates of embryos developed to 2-, 4-, 8∼16-cell and morula/blastocyst stage were 57.2, 48.2, 37.2 and 19.3% in Ham's F-10 with POEC, and 51.4, 41.2, 31.1, and 15.5% in TCM-HEPES with POEC, respectively. The above development rates to morula/blastocyst stages were significantly higher than those of the embryos cultured in the Ham's F-10 and TCM-HEPES with out POEC(P<0.05). The in vitro development rates to the morula/blastocyst stage of 1-cell embryos cultured in Ham's F-10 and TCM-HEPES without POEC were 1.1∼1.2%. Especially, most of embryos were observed to arrest the development beyond 4-cell stages. As shown in the above results, the co-culture of in vitro produced porcine embryos with POEC in the two different media enhanced the development of fertilized eggs to morula/blastocyst stages in vitro. However, we didn't find out any difference for the in vitro development to morula/blastocyst stages between Ham's F-10 and TCM-HEPES media.

• Research in Plant Disease
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• v.18 no.4
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• pp.310-316
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• 2012

Gibberellea fujikuroi species (Gf) complex comprises at least 15 species, most of which not only causes serious plant diseases, but also produces mycotoxins including fumonisins. Here, we focused on the abilities of the field isolates belonging to the Gf complex associated with rice and corn, respectively in Korea to produce fumonisin, all of which were confirmed to carry FUM1, the polyketide synthase gene essential for fumonisin biosynthesis. A total of 88 Gf complex isolates (55 F. fujikuroi, 10 F. verticillioides, 20 F. proliferatum, 2 F. subglutinans, and 1 F. concentricum), and 4 isolates of F. commune, which is a non-member of Gf complex, were grown on rice substrate and determined for their production levels of fumonisins by a HPLC method. Most isolates of F. verticillioides and F. proliferatum, regardless of host origins, produced fumonisin $B_1$ and $B_2$ at diverse ranges of levels ($0.5-2,686.4{\mu}g/g$, and $0.7-1,497.6{\mu}g/g$, respectively). In contrast, all the isolates of F. fujikuroi and other Fusarium species examined produced no fumonisins or only trace amounts ($<10{\mu}g/g$) of fumonisins. Interestingly, the frequencies of relatively high fumonisin-producers among the F. proliferatum and F. fujikuroi isolates derived from corn were higher than those among the fungal isolates from rice. In addition, it is a first report demonstrating the ability of the FUM1-carrying F. commune isolates from rice to produce fumonisins.

• Korean Journal Plant Pathology
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• v.13 no.1
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• pp.46-56
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• 1997

Based on the principal component analysis (PCA) of Richards' parameter estimates, ginseng field soils were grouped as the principal component 1 (PC1) and the principal component 2 (PC2). The microflora and physico-chemical characteristics of each soil group were compared to elucidate soil environmental factors affecting the disease development of root rot of ginseng seedling. Among 3 soil groups by PC1, there were differences in the populations of total fungi (TF) and Cylindrocarpon plus Fusarium (C+F), and the population ratio of Cylindrocarpon plus Fusarium to total fungi or total bacteria (C+F/TF, C+F/TB) in rhizoplane of ginseng seedlings, the population of total actinomycetes (TA) and the population ratio of total Fusarium to total actinomycetes (Fus/TA) in soil, and soil chemical properties (EC, NO3-N, K, Mn, ect.). Among 4 soil groups by PC2, there were differences in TF, C+F, TB, C+F/TF and C+F/TB in the rhizoplane, Trichoderma plus Gliocladium (T+G) in soil, and P2O5 content in soil. Especially, EC, NO3-N, K, K/Mg and Mn were positively correlated to PC1, and TA was negatively to PC1; however, TF, C+F, TB, C+F/TF and C+F/TB in the rhizoplane were significantly correlated to PC2 positively. On the other hand, microbes in the rhizoplane were not significantly correlated to the stand-missing rate (SMR), although TA and Fe/Mn were negatively correlated, and pH and Ca were positively correlated to SMR.

• The Plant Pathology Journal
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• v.17 no.5
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• pp.290-294
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• 2001

Forty(40) isolates of Fusarium oxysporum isolated from wilting tomato plants at Buyeo of Korea in 1997 were inoculated to four tomato cultivars (Ponderosa, Okitsu 3, Walter, and Zuiken) to examine pathogenic reactions. Isolation rates of F. oxysporum f. sp. lycopersici (FOL) races 1 and 2, and F. oxysporum f. sp. radicis-lycopersici(FORL) were 3.5%, 24.5%, and 57.5%, respectively. Mycelial growth on potato-dextrose agar at different temperature for the three pathogens was $26^{\circ}$. In the pathogenicity tests, however, the range of optimum temperature for disease development for FORL was between 15 and $20^{\circ}$, while that for races 1 and 2 of FOL were specifically pathogenic to tomato only. This suggests that host ranges of FORL and FOL differ significantly.

• Korean Journal of Agricultural Science
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• v.49 no.1
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• pp.121-128
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• 2022

Fusarium wilt disease caused by Fusarium species is a major problem affecting cultivated cucurbit plants worldwide. Fusarium species are well-known soil-borne pathogenic fungi that cause Fusarium wilt disease in several cucurbit plants. In this study, we aimed to identify and classify pathogenic Fusarium species from cultivated Korean cucurbit plants, specifically watermelon and cucumber. Thirty-six Fusarium isolates from different regions of Korea were obtained from the National Institute of Horticulture and Herbal Science Germplasm collection. Each isolate was morphologically and molecularly identified using an internal transcribed spacer of ribosomal DNA, elongation factor-1α, and the beta-tubulin gene marker sequence. Fusarium species that infect the cucurbit plant family could be divided into three groups: Fusarium oxysporum (F. oxysporum), Fusarium solani (F. solani), and Fusarium equiseti (F. equieti). Among the 36 isolates examined, six were non-pathogenic (F. equiseti: 15-127, F. oxysporum: 14-129, 17-557, 17-559, 18-369, F. solani: 12-155), whereas 30 isolates were pathogenic. Five of the F. solani isolates (11-117, 14-130, 17-554, 17-555, 17-556) were found to be highly pathogenic to both watermelon and cucumber plants, posing a great threat to cucurbit production in Korea. The identification of several isolates of F. equiseti and F. oxysporum, which are both highly pathogenic to bottle gourd, may indicate waning resistance to Fusarium species infection.

• Journal of Microbiology and Biotechnology
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• v.33 no.6
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• pp.745-752
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• 2023

Gut symbionts play crucial roles in host development by producing nutrients and defending against pathogens. Phloem-feeding insects in particular lack essential nutrients in their diets, and thus, gut symbionts are required for their development. Gram-negative Pantoea spp. are known to be symbiotic to the western flower thrips (Frankliniella occidentalis). However, their bacterial characteristics have not been thoroughly investigated. In this study, we isolated three different bacteria (BFoK1, BFiK1, and BTtK1) from F. occidentalis, F. intonsa, and T. tabaci. The bacterial isolates of all three species contained Pantoea spp. Their 16S rRNA sequences indicated that BFoK1 and BTtK1 were similar to P. agglomerans, while BFiK1 was similar to P. dispersa. These predictions were supported by the biochemical characteristics assessed by fatty acid composition and organic carbon utilization. In the bacterial morphological analysis, BFoK1 and BTtK1 were distinct from BFiK1. All these bacteria were relatively resistant to tetracycline compared to ampicillin and kanamycin, in which BFoK1 and BTtK1 were different from BFiK1. Feeding ampicillin (100,000 ppm) reduced the bacterial density in thrips and retarded the development of F. occidentalis. The addition of BFoK1 bacteria, however, rescued the retarded development. These findings indicate that Pantoea bacteria are symbionts to different species of thrips.

• Journal of Embryo Transfer
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• v.11 no.3
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• pp.217-223
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• 1996

This study was conducted to investigate the effects of co-culture for the development rate to morula /blastocyst stages of early porcine embryos, derived from oocytes matured and fertilized in vitro, with porcine endometrial cell monolayers(PEM) in the two different media, respectively. The rates of embryos developed to 2-, 4-, 8~16-cell and morula /blastocyst stage were 49.6, 40.5, 28.2 and 15.3% in Ham's F-10 with PEM, and 55.3, 45.9, 32.7, and 17.6% in TCM-HEPES with PEM, respectively. The above development rates to morula /blastocyst stages were significantly higher than those of the embryos cultured in the Ham's F-10 and TGM-HEPES without PEM(P<0.05). The in vitro development rates to the morula /blastocyst stage of 1-cell embryos cultured in Ham's F-10 and TCM-HEPES without PEM were 0~1.2%. Especially, most of embryos were observed to arrest the development beyond 4-cell stages. As shown in the above results, the co-culture of in vitro produced porcine embryos with PEM in the two different media enhanced the development of fertilized eggs to morula /blastocyst stages in vitro. However, we didn't find out any differences for the in vitro development to morula /blastocyst stages between Ham's F-10 and TcM-HEPES media.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.1
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• pp.84-88
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• 1984

To obtain basic information on the breeding of early maturing, short plant height rapeseed varieties, the following 7 varieties, Isuzu, Miyuki, Norin 25, Rang, Yongdang, Cresus and Tower were used in diallel crosses in 1979. Maturing date, plant height and grain weight per plant for the parents, $F_1$'s and $F_2$'s of the 7 x 7 partial diallel crosses were measured in 1981 for analysis of their genetic behavior. The results obtained are summarized as follows: 1. The days to maturing of $F_1$'s showed complete dominance for early maturing, and both additive and dominance genetic variances were significant. Number of effective factors in $F_1$'s was 3, but in $F_2$'s was 1. The degree of dominance in $F_1$'s was partial, while in $F_2$'s was complete. Both broad and narrow sense herita-bilities in $F_1$'s was high, while in $F_2$'s was low. 2. Yield per plant in $F_2$'s was controlled by additive component of genetic variance only, but $F_1$'s was different. The degree of dominance in $F_1$'s was complete, while in $F_2$'s was partial. The direction of dominance showed almost complete dominance over high yield and three effective factors was estimated. Yield per plant was controlled by recessive genes. 3. The plant height was controlled by both dominance and additive variance. Dominance was directed toward tall plant height. Number of effective factors was 2, and broad and narrow sense heritability were high in the plant height.