• The Korean Journal of Mycology
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• v.49 no.3
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• pp.399-403
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• 2021

Stem blight symptoms were observed in greenhouse-grown bottle gourds (Lagenaria siceraria) in Wanju, Korea. Infected plants showed leaf chlorosis and wilting; the plants eventually died with the infected leaves remaining attached, and black sclerotia formed on the diseased stem. Based on the morphological characteristics and pathogenicity results and sequence analyses of the internal transcribed spacer, translation elongation factor 1-α, β-tubulin, and calmodulin regions, the isolated fungus was Macrophomina phaseolina. This is the first report of charcoal rot in Lagenaria siceraria caused by Macrophomina phaseolina in Korea.

• Research in Plant Disease
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• v.26 no.2
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• pp.109-115
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• 2020

A disease causing leaf blight and vine rot was recognized on kudzu plants (Pueraria lobata) in Korea since 1991. A species of Phytophthora has been repeatedly isolated from the infected leaves. Identification in species level of the Phytophthora sp. remained unsolved. An isolate, KACC 47616 originally collected from Manchon Park in Daegu, has been kept in our laboratory. In 2013, three new isolates, KACC 47617 and KACC 47618 from Yeongyang and KACC 47619 from Gunwi in Gyeongbuk province, were collected and examined to classify up to species level by characterizing morphology, response to temperature and phylogenetic relationship. On the basis of morphological characters such as the nature of hyphal swelling, sporangia and sex organs, absence of chlamydospore production, optimum temperature for mycelial growth, and internal transcribed spacer rDNA and cytochrome oxidase subunit 1 sequence analysis of the pathogen, the causal fungus of kudzu plant was identified as Phytophthora asiatica.

• Research in Plant Disease
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• v.12 no.2
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• pp.134-138
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• 2006

A new bacterial disease of broccoli (Brassica oleracea var. italica) was observed on field-grown plants in Pyungchang during 2003 and 2004. Seedling infections first appeared as a blackening along the margins of the cotyledon. Cotyledon shriveled and dropped off. Infected seedlings were stunted and yellowed and eventually died. The disease was easily recognized by the presence of yellow, V-shaped, or U-shaped areas extending inward from margin of the leaf. As the disease progressed, the yellow lesions turned brown and the tissues died. Isolations made from diseased leaves on yeast extract dextrose calcium carbonate agar yielded nearly pure cultures of a yellow-pigmented bacterium typical of a xanthomonad. Two bacterial strains were purified and used for further tests. Pathogenicity of strains was confirmed on 3-week-old crucifer (cabbage, Chinese cabbage, kale, radish and broccoli) plants cut by scissors with bacterial suspensions containing $10^8 cfu/ml$ of phosphate buffered saline. The Biolog and fatty acid analyses and 16S rDNA sequencing of two strains (SL4797 and SL4800) from broccoli black rot showed that they could be identified as X. campestris pv. campestris because of their high similarity to the tester strain (X. campestris pv. campestris NCPPB528) with a match probability of 100%. This is the first report of black rot of broccoli in Korea.

• The Korean Journal of Mycology
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• v.50 no.3
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• pp.235-241
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• 2022

Anthracnose crown rot (ACR) has been observed in greenhouses during the nursery and harvest seasons in Gangwon Province, Korea. Infected plants showed black leaf spot, dark sunken pink conidial masses on petioles, wilting, and eventually death. Five isolates were obtained from the lesions of strawberry plants and were identified as a Colletotrichum gloeosporioides species complex based on their cultural and morphological characteristics. Multilocus sequence analysis of actin, calmodulin, chitin synthase, glyceraldehyde-3-phophate dehydrogenase genes, and internal transcribed spacer rDNA regions showed that the isolates formed a monophyletic group with the type strain of C. siamense. Pathogenicity tests were performed on the isolate, and Koch's postulates were performed to verify the relationship between Colletotrichum sp. and the strawberry plant variety Seolhyang. The isolate was pathogenic to strawberry plants, which exhibited typical ACR symptoms. Based on morphological characteristics, pathogenicity, and DNA sequence analyses, the fungus isolated in Korea was identified as C. siamense. This is first time C. siamense has been confirmed in ever-bearing strawberry varieties in Korea.

• Research in Plant Disease
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• v.12 no.2
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• pp.122-124
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• 2006

Sclerotinia rot was occurred on the leaf and stem of Fatsia japonica in Geoje city, Gyeongnam province in Korea from 2004 to 2005. The typical symptom of the disease was water-soaked infected leaves and stems. The colony of the isolated fungus was white to faintly gray in color. Apothecia were cup-shaped with numerous asci and $0.8{\sim}1.3 cm$ in size. Asci were cylindrical in shape and $70{\sim}220{\times}4{\sim}18{\mu}m$ in size. Ascospores were aseptate, hyaline, ellipsoid in shape, and $6{\sim}12{\times}4{\sim}6{\mu}m$ in size. Sclerotia formed on the plants and PDA medium were globose to cylindrical or irregular in shape, black in color. The optimum temperature for mycelial growth was $25^{\circ}C$. This is the first report on the Sclerotinia rot of Fatsia japonica caused by Sclerotinia sclerotiorum in Korea.

• Research in Plant Disease
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• v.27 no.3
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• pp.115-119
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• 2021

Sclerotinia rot was occurred on the leaf and stem of Peucedanum japonicum Thunb. in greenhouse field of Pohang city of Gyeongbuk province in Korea. The typical symptom of the disease was light brown spot and tipburn on infected leaves. The colony of the isolated fungus was white to light gray in color. Asci were cylindrical shape and 75-240×5.9-17.3 ㎛ in size. Apothecia were cup-shaped with numerous asci and 0.5-0.9 cm in size. Ascospores were aseptate and ellipsoid in shape, and 8.4-10.7×4.8-5.8 ㎛ in size. Sclerotia formed on the plants and potato dextrose agar medium were globose to irregular in shape and black in color. Partial sequencing of rDNA of this isolate showed that it was 100% consistent with that of Sclerotinia sclerotiorum. It was confirmed that the same lesion was formed by reinoculating this pathogen on a healthy P. japonicum Thunb. and the same strain was isolated. This is the first report on the Sclerotinia rot of P. japonicum Thunb. caused by S. sclerotiorum in Korea.

• Current Research on Agriculture and Life Sciences
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• v.17
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• pp.7-13
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• 1999

Thirty bacteria were isolated from the red pepper rhizosphere. The isolates were screened for antagonism to Alternaria alteranta causing red pepper black rot. Antagonistic bacterium No. J-24 was selected among the isolated bacteria and was identified as Bacillus subtilis based on morphological and physiological characteristics and MIDI system. B. subtilis J-24 showed antifungal activities against A. alternata(inhibition percentage, 99%), Botrytis cinerea, Phytophthora capsici, Pythium ultimum, Colletotrichum gloeosporioides, Stemphylium botryosum. The growth of red pepper seedling was promoted as compared to control when the microbial inoculants was mixed in bed soil. In the mixed microbial inoculants bed soil, the leaf area of red pepper was increased of 15 percent, the hypocotyl weight 12 percent, the root length 12 percent, total dry weight 13 percent as compared to those grown in the general bed soil.

• Research in Plant Disease
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• v.23 no.1
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• pp.56-59
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• 2017

During growing season of 2011 to 2013, Sclerotinia rot symptoms consistently have been observed on basil in Yesan-gun, Chungcheongnam-do in Korea. The typical symptom formed initially brownish spot on leaf and stem, and then advancing margins, wilting the whole plant and blighting, eventually died. On the surface of diseased lesions was observed cottony, white, dense mat of mycelial growth, and sclerotia ($30-100{\mu}m$ diameter) formed on stem and leaf. Morphological and cultural characteristic on potato dextrose agar, color of colony was white and colorless chocolate, sclerotium of irregular shape of the oval was black and $5-50{\mu}m$ diameter in size. In pathogenicity test, necrosis and wilt of the inoculated stem were observed in all plants and the pathogen was reisolated from stems. On the basis of mycological characteristics, pathogenicity, and internal transcribed spacer rDNA sequence analysis, this fungus was identified as Sclerotinia sclerotiorum. This is the first report of Sclerotinia rot on basil caused by S. sclerotiorum in Korea.

• 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.

• Horticultural Science & Technology
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• v.19 no.1
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• pp.66-70
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• 2001

'Mansoo' is a late-season pear cultivar with extra large and high quality fruit of long storability, which was released by National Horticultural Research Institute in 1995. The cultivar originated from the cross between 'Danbae' and 'Okusankichi' at Suwon in 1978, had been under regional adaptability test at nine areas in the name of 'Wonkyo Na-15' for 4 years since 1992. It was vigorous in tree growth and upright in tree shape. Its flower bud is easily maintained, resulting in higher productivity than 'Danbae' and 'Okusankichi'. It bloomed a day later than 'Niitaka', and showed cross-compatibility with 'Niitaka', 'Chojuro' and some other varieties. Harvesting time of 'Mansoo' is late October in Suwon. The fruit shape is oblate and skin color is light yellowish brown. The fruit weighed 600-700 g and has 12-13% soluble solids content. The flesh is soft, juicy, and has negligible grit. It is resistant to black leaf rot (Alternaria kikuchiana Tanaka).