• Fisheries and Aquatic Sciences
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• v.4 no.4
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• pp.201-207
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• 2001

To study the distribution of organophosphorus pesticides which are extensively used for agriculture in Korea. Sea water samples were taken from 4 coastal areas during May and August of 1997 and sediment samples were collected from two coastal areas in August of 1997. These samples were analyzed using a Gas Chromatography/Nitrogen Phosphorus Detector (GC/NPD). In August the most commonly found organophosphorus pesticides in the surface waters of Kunsan area were IBP < S-Benzyl O,O-di-isopropyl phosphorothioate > $(m=432.5ng\;L^{-1})$ and EDDP < O-ethyl S,S-diphenyl phosphorodithioate > $(m=37.4ng\;L^{-1}) $ which are largely used between June and September to prevent rice blast disease. In Danghang Bay, dry fields located near the mouth of the estuary seemed to affect the concentrations of certain organophosphorus pesticides in the surface waters. Since organophosphorus pesticides applied in the watershed are rapidly decomposed while being transported along freshwater streams, watershed size is not proportional to the concentrations of these pesticides in the coastal waters. Pesticides concentrations measured in August were compared with those in May. IBP concentrations in coastal waters were about an order of magnitude higher in August than in May. Temporal and geographical distribution of individual organophosphorus pesticides is likely to be affected by types of agricultural practices in the watershed. Chloropyrifos was the most important of the organophosphorus pesticides in the sediments of the study area because of its persistent nature and high affinity to particulates.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.84.2-85
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• 2003

Magnaporthee grisea causes the devastating blast disease of rice. Entensive research has been conducted on infection mechanisms, particularly on appressorium formation and penetration, of this fungus during the last decade. However, the role(s) of cell-wall-degrading enzymes (CWDEs) on pathogenesis is not clearly demonstrated at molecular level. Many CWDES in plant pathogenic fungi including M. grisea are redundant; that is, there are multiple genes encoding enzymes with a similar or overlapping spectrum of activities. It is laborious to isolate all of the genes encoding related enzymes and to construct mutants lacking all 9f them. Thus, we considered alternative strategies to address the role of CWDEs in pathogenesis. Since expression of CWDE genes Is repressed by a simple sugar, as the first step, we cloned a Snfl (sucrose non-fermenting) gene (MgSnf1) from M. grisea. The predicted amino acid sequence showed a high identity with other Snf1 genes from various fungi. To elucidate molecular function of MgSnf1, a transformant lacking MgSnf1 was created by targeted gene replacement. En glucose, sucrose, and xylan the MgSnf1 mutant grew normally but in pectin and complex media, it grew slower than wild type. Expression of various CWDEs in MgSnf1 mutant was investigated and found that expression of some CWDEs is repressed. However, no significant difference was observed in conidial germination, appressorium formation, and pathogenicity in MgSnf1 mutant. However, MgSnf1 functionally complemented a yeast MgSnf1 mutant. These results suggest that MgSnf1 is involved in regulation of CWDEs and MgSnf1 is dispensable in pathogenicity of M. grisea.

• The Plant Pathology Journal
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• v.15 no.1
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• pp.14-20
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• 1999

Twenty isolates of Helminthosporium species were obtained from various grass plants and tested for controlling efficacy on the development of plant diseases. An isolate of Helminthosporium sp. TP-4 was chosen and six antibiotic substances were purified from cultures of the fungus by repeated silica gel column chromatography and preparative thin-layer chromatography. They were identified as ophiobolin a, 6-epiophiobolin A, 3-anhydroophiobolin A, 3-anhydro-6-epiophiobolin A, iphiobolin B, and iphiobolin I mainly by mass spectrometry and nuclear magnetic resonance spectrometry. Ophiobolins inhibited the growth of a grampositive bacterium Streptomyces griseus, but were not active against gram-negative bacteria. They also showed an antifungal activity. In in vivo tests, iphiobolin B exhibited potent controlling activities against rice blast, tomato late blight, and wheat leaf rust with control values more than 90% and 70% at concentration of $500\mu\textrm{m}$/ml and 100 ${\mu}{\textrm}{m}$/ml. Ophiobolin A and 6-epiophiobolin A controlled the development of wheat leaf rust more than 80% at concentrations of 100 /ml and $500\mu\textrm{m}$/ml respectively. 3-Anhydro-6-epiophiobolin A was not active against any plant disease. On the other hand, the A-series ophiobolins other than 3-anhydroophiobolin A showed stronger phytotoxic activity in a leaf-wounding assay using 8 plant species than those of 3-anhydroophiobolin A, ophiobolin B, and ophiobolin I. The results indicate that there is little correlation between antifungal activity and phytotoxicity of ophiobolins.

• Korean journal of applied entomology
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• v.13 no.4 s.21
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• pp.245-249
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• 1974

In order to establish a dose limits for subsequent induced mutation research itl Pyricularia oryzae, X-ray sensitivity of the conidia and the vegetative hypae of the fungus, race N-1, was investigated. Conidia of the fungus irradiated with X-rays reduced significantly in spore germination inversely with radiation doses. A severe suppression of conidia germination in about $80\%$ was found at the dose of 120kR, and the rests of the conidia produce very short and lysed germ tubes. A stimulated effect was observed in the elongation of hyphae from the conidia of 10 kR irradiation at initial stage of the growth. The radiosensitivity of hyphae was exremely higher than that of conidia with the increase of radiation doses. It was also recognized that the frequency of X-ray induced mutation in pathogenicity was directly proportional to radiation doses.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.606-610
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• 2011

'Jungmo1001' is an early maturing intermediate breeding line developed from a cross between Cheolweon52 and SR14694-57-4-2-1-3-2-2 by the rice breeding team of National Institute of Crop Science, Rural Development Administration (RDA) in 1994. 'Jungmo1001' has about 107 days duration from seeding to heading in mid-northern inland plain, southern alpine area and north-eastern coastal areas. It has about 73 cm in culm length with semi-erect plant type and good canopy architecture. This variety has 13 tillers per hill and 90 spikelets per panicle. Its 1,000 grain-weight of brown rice is 21.2 g which is less than 26.3 g of 'Odaebyeo'. Milled kernels are translucent with non-glutinous endosperm, low amylose content (18.1%) compared with 'Odaebyeo' palatability of cooked rice is very good. This variety shows strong resistance to cold treatment, lodging, premature heading and wilting. This variety shows moderately resistant to blast disease but susceptible to bacterial blight, stripe virus and insect pests. The milled rice yield performance of this variety is about 5.45 MT/ha by ordinary culture in local adaptability test for three years. This variety may be highly adaptable to the mid-northern inland plain, southern alpine area and north-eastern coastal areas of Korea.

• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.328-331
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• 2008

Hwangeumnodeul is a new japonica rice cultivar developed from a cross between Milyang165 and HR15151-B-21-3 at Honam Agricultural Research Institute (HARI), NICS, RDA, in 2007. This cultivar has short grains and about 139 days of growth duration from direct seeding to harvesting in the southern plain areas. Culm length of this cultivar is 78 cm and the number of spikelet per panicle is similar to that of the check cultivar, Nampyeongbyeo, while filled grain rate is lower than the check variety. This cultivar is moderately resistant to leaf blast, bacterial blight pathogens of $K_1$, $K_2$ and $K_3$ and stripe virus but susceptible to major virus diseases and insect pests. Milled kernel of Hwanggeumnodeul is translucent with non-glutinous endosperm. This cultivar has about 5.7% and 18.6% of protein and amylose contents, respectively. Palatability of cooked rice of Hwanggeumnodeul is similar to Nampyeongbyeo. Its milling recovery and head rice were 75.6% and 90.0%, respectively. Hwanggeumnodeul yielded 5.69 and 5.61 MT/ha in milled rice at the under wet-direct and dry-direct seeding conditions, respectively which are 17% and 12% higher than the check variety, Juanbyeo. It yielded 5.86 MT/ha, 8% higher than Nampyeongbyeo at the standard fertilizer level of the ordinary transplanting cultivation. "Hwanggeumnodeul" would be adaptable for ordinary transplanting as well as direct seeding in the southern plain including Chungcheong province.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.595-599
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• 2011

'Goami 3' is a new japonica rice cultivar developed from a cross between Suweon464 and Daeanbyeo by the rice breeding team of National Institute of Crop Science, RDA. 'Goami3' has about 130 days growth duration from transplanting to heading in central plain area of Korea. It has a good semi-erect plant type and resistance to lodging of about 79 cm in culm length. 'Goami 3' had 15 panicles per hill and 104 spikelets per panicle. 'Goami 3' has very high amylose (29.5%) and high non-dietary starch compared with Hwaseongbyeo. This rice variety has slow senescence and 47% tolerance to viviparous germination during the ripening stage. 'Goami 3' is susceptible to leaf blast, bacterial blight, virus disease and insect pest. The yield performance of this cultivar in milled rice was about 3.92MT/ha by ordinary season culture in local adaptability test from 2005 to 2007. 'Goami 3' is adaptable to central and southern plain area of Korea.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.581-586
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• 2011

'Cheongdam' is a japonica rice variety developed from a cross between SR19200-HB826-34, a line of good germination ability and shoot emergence at low temperature and Juanbyeo, good quality and direct-seeding adaptable cultivar by the rice breeding team of National Institute of Crop Science, RDA in 2006. This variety has 153 days of total growth duration from seeding to maturity in direct-seeding, and 160 days of growth duration from seeding to maturity in transplanting. This is erect plant type with culm length of 74 cm, thick culm, and green leaves. It has large panicle shape with 126 and 140 spikelets per panicle in direct-seeding and transplanting, respectively. Milled rice is transluscent and medium in grain size of non-glutinous endosperm. This variety is susceptible to leaf and neck blast, bacterial blight, stripe virus disease and brown planthopper. The yield potential of 'Cheongdam' is 5.84 MT/ha at ordinary transplanting culture and 5.62 MT/ha and 5.89 MT/ha at wet direct-seeding and dry direct-seeding cultures, respectively in the local adaptability test for three years. 'Cheongdam' would be adaptable to middle and southern plain of Korea for direct-seeding culture and transplanting rice culture.

• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.257-261
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• 2010

'Manmibyeo', a new japonica rice cultivar, is a mid-late maturing ecotype cultivar developed by the rice breeding team of Department of Functional Crop, NICS, RDA in 2002. This cultivar was originated from the cross between 'Milyang 95' and $F_1$ of the cross between 'Bukrukbanna' and 'Milyang 95' in 1990/1991 winter season. It was selected by pedigree breeding method until F6 generation, and a promising line, YR14545-9-2-3-4, was advanced and designated as 'Milyang 162' in 1996. The local adaptability test of 'Milyang 162' was carried out at seven locations during 3 years in 1997, 1998 and 2002. It has about 86cm culm length and is lodging tolerant. This cultivar is susceptible to bacterial blight ($K_1$, $K_2$, $K_3$) and stripe virus, and moderately resistant to leaf blast disease. Milled rice kernels of 'Manmibyeo' is translucent with low amylose content in endosperm, clear in chalkiness and good at eating quality in panel test. The yield potential of 'Manmibyeo' in milled rice was about 4.46 MT/ha at ordinary fertilizer level in local adaptability test. This cultivar would be adaptable to the southern plain of Korea.

• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.262-266
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• 2010

'Josaengheugchal', a new blackish purple pigmented glutinous japonica rice cultivar, was developed by the rice breeding team of Department of Functional Crop, NICS, RDA in 2004. This cultivar was derived from a cross between 'Tohoku 149' as black glutinous source and 'Sx 864' as purple colored rice in 1992 and 1993 winter season, and selected by pedigree breeding method until $F_6$ generation. As a result, a promising line, YR15907-6-8-1-5, was advanced and designated as the name of 'Milyang 194' in 2001. The local adaptability test of 'Milyang 194' was carried out at seven locations from 2002 to 2004 and it was named as 'Josaengheugchal'. 'Josaengheugchal' is an early maturing cultivar and has 71 cm culm height. It has higher anthocyanian content compared with 'Heugnambyeo'. It is moderately resistant to leaf blast but susceptible to other disease and insect pests. The yield potential of 'Josaengheugchal' in brown rice was about 4.21 MT/ha at ordinary fertilizer level in local adaptability test. This cultivar would be adaptable to the plain paddy field of middle, Honam, and Yeomgnam in Korea under ordinary and double cropping system.