• Korean Journal of Agricultural Science
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• v.25 no.1
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• pp.118-123
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• 1998

Lasiodiplodia theobrorme is a pathogen of Java black rot on sweet potato. This fungus infects the tuberous root during storage after harvest. Invasion of the fungus results in the expansion of necrosis sites into the tuberous roots. The resultant necrotic symptom of the tissue is also induced by application of acetone extract of the fungus growing on potato sucrose agar (PSA) culture. The active principles to induce the necrosis are purified from the acetone extract as follows. After evaporation of hexane-benzene-EtOAc (1:2:1, v/v/v) the extract was fractioned on silica gel column, using a solvent gradient system from n-hexane to EtOAc and then to MeOH. The active fractions were purified with HPLC on Nucleosil 50-5 column by eluting n-hexane to EtOAc. Their structures are established by using spectroscopic techniques and synthesis to 4-hydroxymellein and mellein, respectively. Application of small amount of these compounds induce expansion of the necrotic symptom into the tissue and accumulated ipomeamarone. Conclusively, these compounds acted as phytotoxins (inducing necrosis) and as elicitors (eliciting the phytoalexin).

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.612-615
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• 2009

Lipoxygenase and Kunitz trypsin inhibitor protein are the main antinutritional factor in mature soybean seed. A new soybean cultivar, "Gaechuck#2" with yellow seed coat, lipoxygenase2,3-free and Kunitz trypsin inhibitor protein-free was developed. It was selected from the population derived from the cross between "Jinpumkong2ho" and C242. Plants of "Gaechuck#2" have determinate growth habit with purple flowers, tawny pubescence, yellow seed coat, yellow hilum, oval leaflet shape and brown pods at maturity. Seed protein and oil content on a dry weight basis were 40.7% and 18.7%, respectively. It has shown a resistant reaction to soybean necrosis, soybean mosaic virus, Cercospora leaf spot and blight, black root rot, pod and stem blight, and soybean pod borer. Gaechuck#2 matured in 4 October with plant height of 54cm and a 100-seed weight of 24.4g. Average Yield of Gaechuck#2 was 230 - 250 kg/10a in 2005 - 2007.

• Journal of Korean Society of Forest Science
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• v.96 no.5
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• pp.585-590
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• 2007

Rhizina undulata is the fungus, which causes Rhizina root rot on coniferous trees. Nested-PCR using ITS-specific primer was applied to detect R. undulata from the soils of Japanese black pine (Pinus thunbergil) forests infested with the disease in Seocheon, Chungnam Province, South Korea. Soil samples were collected from four different sites, both dead trees and fruit bodies of R. undulata were present, dead trees only present, fruit bodies only present, and both were absent. Nested-PCR products specific to R. undulata ITS-region were amplified. Positive reactions were found in some samples from the sites, where dead trees and fruit bodies of R. undulata were absent as well as where both of those were present. R. undulata was mainly detected in the soil samples from the depth of 5~20 cm under the soil surface. These results show that the nested-PCR could be used to diagnose the presence or potential infestation of R. undulata in the soils of pine forests.

• Korean journal of applied entomology
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• v.20 no.3 s.48
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• pp.135-145
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• 1981

Vegetables including Chinese cabbage and radish have been grown in alpine areas such as Muju, Namweon, Jinan and Jangsu during the shortage period of vegetables. The incidence of various diseases, environmental factors such as temperatures and rainfalls, and aphid populations as virus vector were observed at 10-day intervals from July to September in those areas. Disease incidence showed no significant difference among locations. Major diseases in Chin ese cabbage were bacterial soft rot, white spot, downy mildew, mosaic virus, Alternaria leaf spot and Fusarium seedling blight. Major diseases in radish were virus, white rust, black rot, root rot, leaf spot and Fusarium seedling blight. Disease incidence reached peak on Aug. 20 with $27\%$ infection in radish and with $20\%$ infection in Chinese cabbage during the growing season, and declined thereafter. Percentage of infection in each growth stage showed $25\%$ at root thickening stage and $26\%$ at the harvest time in radish; and the head formation stage, $24\%$ at the harvest time. The data indicate that disease incidence in radish increased rapidly at late growing stage and progressively increased in Chinese cabbage Seedling blight caused by Fusarium sp. and root rot caused by Aphanomyces sp. were also observed in those areas. Cool and wet weather appeared to be favorable for disease incidences during the rainy period of growing season although average temperature was about $25^{\circ}C$. Populations of aphids were lower in the alpine vegetable growing area than that of flat areas. Aphids as virus vectors from total aphids collected were $73.5\%$ or 289 virus vectors /993 total aphids in Namweon and $18.1\%$ or 31 virus vectors/171 total aphids in Muju. The most prerevalent species of aphids was Myzus persicae Sulz.

• 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.

• Research in Plant Disease
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• v.17 no.2
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• pp.148-154
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• 2011

This study was conducted to control the seed borne pathogens (Alternaria spp.) of carrot and to examine the seed germination rate by using 13 environment friendly agricultural materials instead of conventional chemicals for organic cultivation. The growth inhibiting effects on pathogens showed the different responses according to each agricultural material and effective 7 materials against seed borne pathogens were selected. Among 7 materials, the carrot seeds sterilized with plant extracts, Tanger Stop and Land Saver were not germinated at all. The germination rate of seeds sterilized with other materials showed the similar levels with reference chemical (Benlate-T) and non-treated seeds. Infection rates of seeds sterilized with seaweed extract, Bellopper for controlling A. radicina and plant extract, Ssial-100 for A. dauci were similar or low infection rate compared with reference chemical. The germination rate and root length of seeds sterilized with Bellopper and Ssial-100 was similar or superior to those of chemical sterilized seeds. The optimal condition seemed to be a little bit different depending on the concentration of materials. As a result, the sterilization of carrot seeds by using the environment friendly materials could be effectively utilized as a technology to inhibit the infection of seed-borne pathogens.

• The Korean Journal of Mycology
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• v.46 no.3
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• pp.255-269
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• 2018

Armillaria is a white-rot fungus that decomposes organics; it is also a root pathogen that kills trees. Recently, since the forest tending practice, the incidence of Armillaria infections on tree stumps has been increasing. Herein, we have examined the morphological features of Armillaria solidipes and A. gallica collected from 10 areas in Korea, and investigated the activities of the decomposing enzymes cellulase and laccase of these two Armillaria species. A. solidipes was found in eight host tree species including Pinus densiflora, Quercus serrata, and Castanea crenata at the altitude of 107~1,396 m, while A. gallica was found in three host species including P. densiflora and Fraxinus rhynchophylla at the altitude of 119~556 m. The fruiting bodies of A. solidipes are close with lamellae, and have brown to black hairs on the stipe, while those of A. gallica are distant with lamellae and clavate-shaped, and have yellow hairs on the base. The activites of cellulase of the two species were not different, but the activity of A. solidipes laccase was higher ($12.94{\pm}0.4U/mL$) than that of A. gallica laccase ($9.14{\pm}0.3U/mL$).

• 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".

• Korean Journal of Organic Agriculture
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• v.19 no.3
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• pp.357-372
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• 2011

We carried out the experiment to select the suitable sprout soybean varieties for environment-friendly cultivation in paddy field of southern part area, compares of excess moisture injury degree and yield ability among 29 sprout soybean varieties. Plant growth of sprout soybean was generally low in beginning and recovered after flowering due to rainfall. In paddy field cultivation, number of pod per individual and number of seed per individual were less in difference than upland cultivation, and maturing date was delayed 5-14 days than upland cultivation in most species. When environment-friendly cultivation, pest injury was not caused major problem for the growth during the vegetative period of soybean due to ground spider as natural enemy to insect pest. However, damage of stink bugs showed severe during grain filling period, and Dawonkong, Anpyeongkong, Dachaekong and Wonhwangkong showed susceptible to sting bug. SMV infection was weak and showed some necrosis symptoms in Sokangkong, but black root rot was not infected at all. Bacterial pustule began to be infected slowly from pod enlargement stage in most species, displayed severe symptoms in Dawonkong, Pungsannamulkong, Seonamkong and Sobaeknamulkong. The symptoms of pod anthracnose, pod blight and purple spot were greatly appeared after flowering. Disease resistance varieties was Paldokong, Kwangankong, Doremikong, Somyeongkong, Pungsannamulkong, Iksa-namulkong, Seonamkong, Sojinkong, Pureunkong, Bosugkong, Namhaekong and Sorokkong. Lodging index showed 3 in Saebyeolkong, and other species displayed slight lodging in 0-3 degree. 100-seed weight is 9.8-17.2g extent and increased 0.1-3.7g than upland cultivation in most species, but decreased in some species. Government purchase standard, species correspond to small-seed-size namulkong (Sizing screen diameter 4.0-5.6 mm) was Dawonkong, Dachaekong, Bosugkong, Seonamkong, Sokangkong, Hannamkong, Somyeongkong and Wonhwangkong. Species which seed yield was higher than Pungsannamulkong (266kg/10a) were Sorokkong, Hannamkong, Bosugkong and Sowonkong. Considering sprout soybean species, disease endurance, insect resistance, lodging resistance, 100-seed weight, yield ability and excess moisture tolerances synthetically, Seonamkong, Hannamkong, Doremikong, Bosugkong, Pungwonkong, Kwangankong, Sowonkong, Dagikong, Paldokong, Eunhakong and Pungsannamulkong were promising for environment-friendly cultivation in paddy field.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.640-644
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• 2009

A new sprout-soybean cultivar, "Sohwang" was developed at the National Institute of Crop Science (NICS) in 2008. "Sohwang" was selected from a cross between Pungsan and Pungsan/Nattosan. The preliminary, advanced, and regional yield trials to evaluate the performance of Iksan 58 were carried out from 2004 to 2008. This cultivar has a determinate growth habit with purple flower, grayish brown pubescence, yellow seed coat, Yellow hilum, lanceolate leaflet shape and small seed size (8.5 grams per 100 seeds). The maturity date of "Sohwang" is 10 days earlier than the check variety, "Pungsan". It has a good seed quality for soybean-sprout. The soybean-sprouts grown from "Sohwang" have high isoflavone ($3,041{\mu}g/g$)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. Especially, "Sohwang" has useful characteristics, such as lodging and shattering resistance. The average yield of "Sohwang" was 2.69 ton per hectare in the carried out for three years from 2006 to 2008 regional yield trials(RYT) for double cropping.