• Korean Journal Plant Pathology
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• v.14 no.4
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• pp.287-293
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• 1998

Bipolaris coicis, B. cynodontis, B. maydis and Curvularia lunata were leaf blight fungi detected from 45 seed samples of Job's tears and B. coicis was the predominant species in seed samples followed by C. lunata, B. cynodontis and B. maydis. When the seed components were plated on test tube agar, B. coicis and C. lunata were highly detected from invelucre, glume, endosperm and stamen, but not detected from plumule. Seed infection with B. coicis casued seed rot, coleoptile blight and seedling blight of Job's tears. Conidial characteristics of leaf blight fungi were as follows; B. cynodontis was fusiform, brown, slightly curved, 0~5 distoseptate, and 16.8-48$\times$7.2-16.8${\mu}{\textrm}{m}$ in size; B. cynodontis was fusiform, brown, slightly curved, 0~8 distoseptate, and 16.8-72$\times$9.6-19.2 ${\mu}{\textrm}{m}$; B. maydis was fusiform, brown, distintly curved, 0~10 distoseptate, and 28.8-110.4$\times$12-21.6 ${\mu}{\textrm}{m}$. C. Lunata was fusiform, brown, typically curved, 0~3 distoseptate, and 7.2-24$\times$4.8-12 ${\mu}{\textrm}{m}$. B. coicis was highly pathogenic to Job's tears and corn, weakly pathogenic to rice, but not pathogenic to wheat and barley. c. lunata was highly pathogenic to Job's tears (No. 2), corn, wheat and barley, weakly pathogenic to Job's tears (No. 1), but not pathogenic to rice. All treatments were effective to inhibition of leaf blight fungi when carboram, benoram, fludioxonil, prochloraz, thioram, and tap water treated to infected seeds.

• The Plant Pathology Journal
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• v.27 no.2
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• pp.103-109
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• 2011

The fungal genus Cercospora is one of the most ubiquitous groups of plant pathogenic fungi, and gray leaf spot caused by C. zeae-maydis is one of the most widespread and damaging foliar diseases of maize in the world. While light has been implicated as a critical environmental regulator of pathogenesis in C. zeae-maydis, the relationship between light and the development of disease is not fully understood. Recent discoveries have provided new insights into how light influences pathogenesis and morphogenesis in C. zeae-maydis, particularly at the molecular level. This review is focused on integrating old and new information to provide an updated perspective of how light influences pathogenesis, and provides a working model to explain some of the underlying molecular mechanisms. Ultimately, a thorough molecular-level understanding of how light regulates pathogenesis will augment efforts to manage gray leaf spot by improving host resistance and disease management strategies.

• The Korean Journal of Mycology
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• v.29 no.2
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• pp.110-115
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• 2001

Nine species of Bipolaris, two species of Drechslera and two species of Exserohilum were identified from 66 isolates collected from leaf spots and leaf blights on gramineous hosts of field crops, grass pasture plants, turfgrasses and wild weeds in Korea in 1998. They included B. bicolor, B. coicis, B. cynodontis, B. maydis, B. oryzae, B. panici-miliacei, B. setariae, B. sorghicola, B. sorokiniana, D. dictyoides, D. graminea, E. oryzicola and E. turcicum. Of these, B. bicolor, B. sorghicola, D. dictyoides, and E. oryzicola were recorded for the first time in Korea.

• Journal of Microbiology
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• v.33 no.2
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• pp.154-159
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• 1995

SH-14, a novel killer strain of Ustilago maydis was isolated in Korea. It has been reported in other papers that the toxin specificity and double-stranded RNA pattern of SH-14 strain were different from other laboratory strains. In this paper, we analyzed the biochemical characteristics of U. maydis SH-14 virus. Three distinctive peaks were isolated from CsCl density gradient, designated as top (T), intermediate (I) and bottom (B) components. We found that the densities of each components, 1.285, 1.408 g/cm$\^$3/, respectively, are very similar to those of other strains. As previously reported by the analysis of dsRNA in each component, the dsRNA segments are separately encapsidated. Capsid protein of SH-14 virus consists of two proteins about 70 Kd shown by SDS-PAGE analysis. Electron microscopic examination of the virus particles revealed that UmV particles are very similar in size and morphology to all isolates as well as all lab-strains. In order to test immunological cross reactivity of UmV, werstern bolt analysis was carriedout with antiserum against A8 virus. All capsid protein had positive reaction against A8 antibody which indicated that UmV are immunologically cross-reactive with all isolates from Korea. The results presented in this paper may show that UmV isolated from SH-14 strain has very similar biochemical characteristics to those of other UmV. However, the difference in the toxin specificity and the molecular weight of toxin protein from the SH-14 strain has us to conclude that U. maydis SH-14 strain is a new killer type.

• The Korean Journal of Mycology
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• v.24 no.4 s.79
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• pp.293-304
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• 1996

A bacterial strain, KSl, possessing strong antifungal activity was isolated from soil samples of ginseng fields and identified as Bacillus subtilis. In greenhouse test, the culture filtrate of B. subtilis KS1 showed strong protective effect against several fungal diseases of agricultural plants such as cucumber gray mold and wheat leaf rust. In addition, the crude butanol fraction of the culture filtrate exhibited antagonistic effect against several fungi including plant or human pathogens, such as Botrytis maydis, Chytridium lagenarium and Candida albicans. The antifungal compound, SW1, produced by B. subtilis KS1 was purified through consecutive chromatographic separations on a pep-RPC column and a ${\mu}$ Bondapak $C_{18}$ reverse phase column. Temperature and pH showed little effect on the stability of the compound in the ranges $-20-121^{\circ}C$ and pH 4.0-10.0, respectively. The composition and structural characteristics of SW1 were analysed by HPLC and by $^1H-,\;^1H-^1H-COSY$, NOESY, COSY-NOESY and HOHAHA NMR spectroscopy, respectively, which revealed that the compound belongs to iturin A, a typical cyclic antifungal compound produced by B. subtilis. In contrast to the previously reported iturin A compounds which have one or no $-CH_3$ side chain in the hydrophobic hydrocarbon chain of ${\beta}-amino$ acids, SW1 was shown to have a ${\beta}-amino$ acid containing 12-carbon skeleton with two $-CH_3$ side chains.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.4
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• pp.259-264
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• 2002

DK 754S, a forage corn hybrid is bred by Dekalb plant Genetics Co.. Garst 8255 by Garst Seeds Co., and GW 737 by Crosbyton Co. in US, respectively. These have been tested in Suwon and Chonan for 3 years to test their regional yield trial. In result, we were able to confirm the excellence of above cultivars and these were selected as new recommended cultivars April of 2002 by NACF. The characteristics of these cultivars are as follows ; 1. DK 7545 a. This cultivar is mid-late maturing, high quality, high yielding forage corn hybrid. Its mean tasseling date is the 11th of July. It takes 78 days from emergence to tasseling date, which is almost same with Kwanganok. The culm length and the ear height are 231 cm and 127 cm. It is relatively strong to lodging. b. The color of ear is yellow, the number of ear row is nineteen. DK 7545 shows strength to H maydis and MBSDV has occurred between 0% and 4.1% in Chonan test area but it still does not affect yielding at all. It is relatively resistant to corn borer and its stay green is almost same level comparing to a check hybrid, Kwanganok. c. Dry matter yield of this cultivar is 19.6 tons, TDN is 13.4 tons per a ha, therefore these hybrids are increased by from 6 to 9% comparing to Kwanganok. The percent ear among total dry matters yield is 43.7%. 2. Garst 8255 a. This hybrid is mid-late maturing, high quality, high yielding forage corn like as Kwanganok. Its the mean tasseling date and the period from emergence to tasseling date are almost same with a check hybrid, Kwanganok. The Culm length and the ear height are 259 cm, and 146 cm which are tall. It resists to lodging and shows excellence of stay green. b. Garst 8285 resists to H maydis, and MBSDV, and corn borer as much as Kwanganok has. c. Dry matter yield of this cultivar is 21,735 kg. TDN is 14,627 kg per a ha, therefore this is increased by 21%, 16%, respectively, comparing to a check hybrid, Kwanganok. The percent ear among total dry matters yield is 44.2%. 3. GW 737 a. This hybrid is mid-late maturing, high quality, high yielding forage com hybrid like as Kwanganok. Its mean tasseling date is 13th of July which is 2 days late comparing with a check hybrid, Kwanganok and the period from emergence to tasseling date is 80 days. b. The culm length and the ear height are 274 cm and 150 cm, which are tall. It resists to lodging moderately and shows excellence of stay green. c. GW 737 resists to H maydis and MBSDV very well, corn borer moderately resistance. d. Dry matter yield of this cultivar is 18,025kg, TDN 15,164kg per a ha, therefore this hybrid remarkably increased by 26%, 20%, respectively, comparing to a check hybrid, Kwanganok.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.4
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• pp.253-258
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• 2002

NC+4880, a forage com hybrid, is bred by NC+hybrids Co. in US, and Gast 8396 IT is by Garst Seeds Co. We have tested these two cultivars in Suwon and Chonan over three years to test their regional yield trial. Through above experiments, the excellence is testified, in result, they are determined as new recommended cultivars by NACF. The main characteristics of these cultivars are as tallows ; 1. NC+4880 a. The seed coat is yellow, the mean tasseling date is 7th of July and it takes about 74 days from emergence to tasseling date. This hybrid is a day ahead and the culm length is 242 cm, moreless shorter comparing with a check hybrid, Suwon 19. The ear height 117 cm which is short and its stay green is moderate. b. It shows resistance to H maydis, and MBSDV is barely observed and its stay green is moderate. c. The fresh yield, dry matter yield, and TDN yield per a ha are 55.4 tons, 18.3 tons, 12.4 tons, respectively, which are increased by 6%, 7%, and 9%, respectively, comparing with a check hybrid, Suwon 19. The percent ear among total dry matter yield is 50.9%. 2. Garst 8396 IT a. The seed coat is yellow, the mean tasseling date is 9th of July and it takes about 76 days from emergence to tasseling date. This hybrid represent a day delayed compared with a check hybrid, Suwon 19. The Culm length and the ear height are 275 cm, and 138 cm, respectively. b. It resists moderately to H. maydis, and highly resists to lodging in the field conditions. MBSDV is barely observed and its stay green is moderate. c. The fresh yield per a ha is 64.9 tons, dry matter yield, 20.9 tons, and TDN, 13.8 tons, respectively, which are increased by 25%, 23%, and 22% comparing with a check hybrid, Suwon 19. The percent ear among total dry matters is 43.3%.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.4
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• pp.247-252
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• 2002

“DK 537”has been selected by forage crop breeding team at the National Livestock Research Institute(NLRI), RDA and has been determined by the Deliberative Council of the National Agricultural Cooperative Federation(NACF) in 2002, as a new recommended hybrid which is early maturing, good quality and hi호 yield of corn for silage. The characteristics of this hybrid are as follows ; 1. The seed coat is yellow and the mean of tasseling date is 5th of July, included in early maturing hybrid which is one day delayed than check cultivar, DK 501. The culm length is 246cm. It is resistant to lodging because of its low height from surface to ear. 2. DK 537 shows resistance to H. maydis and Maize Black-Streaked Dwarf Virus(MBSDV). It also shows strength to corn borer as much as DK 501 does. 3. Fresh yield. dry matter yield. and TDN per a ha are 50 tons, 16.9 tons, and 11.4 tons respectively. which are almost same yielding level of DK 501. Its percent ear to total dry matter is 50.8% at the same time. Through all these tests, we could make sure at DK 537 hybrid will be recommended as good forage crop.