• The Plant Pathology Journal
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• 제15권1호
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• pp.44-47
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• 1999

Fungal isolates belong to Fusarium solani (perfect stage : Nectria haematococca) were isolated form pea, ginseng roots and soybean during 1995 and 1996 in Korea. Thirty-five isolates were identified as F. solani f. sp. pisi based on the morphological characteristics and their pathogenicity. Microconidia formed on the long conidiophore were ovoid or oblong sizing 5~14 x 2.5~5.0 $\mu\textrm{m}$. Macroconidia were formed on carnation leaf agar media with 4.8~5.3 x 32.0~40.7 $\mu\textrm{m}$ in size. They belonged to $\beta$-type since their 3-septate macroconidia were smaller than $5\mu\textrm{m}$ in width. Chlamydospores were smooth- or rough- walled and formed in terminal or lateral branches of hyphae, intercalary, or in chains. Most isolates were highly virulent to pea seedlings, producing dark brown or rot lesions. This is the first report of f. solani f. sp. pisi being pathogenic to pea in Korea.

• 농업생명과학연구
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• 제50권2호
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• pp.25-32
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• 2016

A severe outbreak of gray mold on kenaf (Hibiscus cannabinus L.) was observed on kenaf grown in the research field of Gyeongsangnam-do Agricultural Research and Extension Services, Jinju, Korea in 2014. Gray mold appeared on young plants as gray-brown velvety mold covering stems and leaves. Infections that girdled the stem caused wilting above the infected area and developed a canker. The casual fungus formed grayish brown colonies on potato dextrose agar. The conidia were one celled, mostly ellipsoid or ovoid in shape, colorless or pale brown in color, and 6-18 × 4-10 ㎛ in size. The conidiophores were 15-32 ㎛ in length. These measurements and taxonomic characteristics were most similar to those of Botrytis. DNA sequencing and phylogenetic analysis of the complete internal transcribed spacer rRNA gene region confirmed that the fungal isolates were indeed Borytis cinerea. Koch's postulates were supported by pathogenicity tests conducted on healthy plants. On the basis of mycological characteristics and pathogenicity test on host plants, the fungus was identified as Botrytis cinerea. To the best of our knowledge, this is the first report of a gray mold caused by B. cinerea on kenaf in Korea.

• 식물병연구
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• 제13권2호
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• pp.122-125
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• 2007

2006년 부산광역시 강서구 칼란코에 재배포장에서 잎에 점무늬병이 심하게 발생하였다. 이병 식물체를 채집하여 병징을 관찰하고 병원균 분리한 다음 균학적 특성을 조사한 결과는 다음과 같다. 병징은 잎의 앞뒤에 갈색 또는 암갈색의 작은 점무늬가 나타나는데, 아래 잎에서부터 병반이 생기고 크기는 $1{\sim}5\;mm$로 약간 괴사되면서 심할 경우 낙엽되었다. 균총은 벨벳트색, 회색 또는 회갈색이며 균사 생육적온은 $25^{\circ}C$와 $30^{\circ}C$이었다. 분생포자는 단생, 갈색이며 실린더, 곤봉형 또는 장타원형으로 횡격막이 $1{\sim}4$개 있으며 크기는 $24{\sim}65\;{\times}\;12{\sim}23\;{\mu}m$이었다. 분생포자경은 갈색, 격막은 $1{\sim}7$개가 있으며, 크기는 $32{\sim}135\;{\times}\;4{\sim}8\;{\mu}m$이었다. 이상과 같은 특징을 가진 병원균이 Stemphylium lycopersici임을 확인할 수 있었다. 따라서 이상의 결과를 종합해 볼 때 칼란코에 잎에 발생한 점무늬 증상을 S. lycopersici (Enjoji) Yamamoto에 의한 칼란코에 점무늬병이라고 명명할 것을 제안한다.

• 한국균학회지
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• 제43권4호
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• pp.239-246
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• 2015

참나무와 소나무 목재에서 분리한 Gyrodontium sacchari 균주에 대한 균학적 특성과 목질계 섬유소 분해력을 검정하였다. 균주는 참나무와 소나무 목재에서 분리하였으며 배지는 potato dextrose agar (PDA)에서 가장 생장이 좋았고 생장온도는 참나무에서 분리한 NAAS02335 균주는 $25^{\circ}C$에서, 소나무 목재에서 분리한 NAAS05299 균주는 $30^{\circ}C$에서 가장 우수한 생장을 보였다. 섬유소 분해 효소인 cellulase와 xylanase, amylase의 활성은 G. sacchari NAAS05299 균주가 6.7~12.8배 더 높았으며 리그닌 분해 효소는 G. sacchari NAAS02335 균주가 3.7~138.5배 활성이 더 높았으며 목질계 섬유소를 탄소원으로 첨가하였을 때 효소의 활성은 월등히 증가하였다. 목질계 바이오매스 분해력을 검정한 결과 G. sacchari NAAS05299 균주는 filter paper를 4주만에 완전히 분해하였고 볏짚과 미송, 참나무를 분해하였으나 G. sacchari NAAS02335 균주는 볏짚에서만 분해력을 나타내어 G. sacchari NAAS05299 균주가 더 우수한 바이오매스 분해 효과를 나타내었다.

• The Plant Pathology Journal
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• 제15권4호
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• pp.228-235
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• 1999

Genetic diversity of ninety-five Korean isolates of Phytophthora was investigated on the basis of PCR-RFLP of ribosomal DNA. The isolates were previously identified as following fifteen species by mycological and cultural characteristics; P. boehmeriae, P. cactorum, P. cambivora, P. capsici, P. cinnamoni, P. citricola, P. citrophthora, P. cryptogea, P. drechsleri, P. erythroseptica, P. infestans, P. megasperma, P. nicotianae, P. palmivora and P. sojae. The regions of small subunit (SSU) and internal transcribed spacer (ITS) of rDNA were amplified with primer pair, NS1 and ITS4, by polymerase chain reaction (PCR) and digested with nine restriction enzymes. P. boehmeriae, P. cactorum, P. cambivora, P. capsici, P. cinnamomi, P. citricola, P. citrphthora, P. infestans, P. nicotianae and P. palmivora showed specific band patterns for each species. However, P. sojae and P. erythroseptica presented identical band patterns and P. cryptogea, P. drechsleri and P. megasperma were divided into six groups, which were not compatible with delineation of the species. A group originated from cucurbits showed distinct band patterns from other groups, but the other five groups were closely related within 96.0% similarity, forming one complex group. Consequently, Korean isolates of Phytophthora were divided into thirteen genetic groups and each group was readily differentiated by comparing digestion patterns of AvaII, HaeIII, MboI, HhaI and MspI. Therefore, PCR-RFLP of rDNA using the five enzymes can be used to differentiate or identify the Phytophthora species reported in Korea so far.

• The Plant Pathology Journal
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• 제21권2호
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• pp.164-166
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• 2005

Corynespora leaf spot occurred severely on balsam pear (Momordica charantia) at Changwon, Gyeongnam province in Korea in November and December 2003. The causal fungus isolated from infected leaves of the plants grew well on potato dextrose agar showing gray to brown color. Solitary or catenary conidia of the fungus were obclavate to cylindrical in shape, and pale olivaceous brown or brown in color. The number of isthmus pseudosepta ranged from 4 to 20 and measured 36~186${\times}$8~19 ${\mu}m$ in size. Conidiophores were pale to light brown in color and measured 94~648${\times}$3~8 ${\mu}m$ in size. Optimal temperature for mycelial growth was $30{\circ}C$. On the basis of mycological characteristics and pathogenicity, the fungus was identified as Corynespora cassiicola (Berk. & Curt.) Wei. This is the first report on the corynespora leaf spot of M. charantia caused by C. cassiicola in Korea.

• 아시안잔디학회지
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• 제14권1호
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• pp.241-250
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• 2000

In 1997, a new disease on creeping bentgrass and Kentucky bluegrass occurred in the green and fairway of a few golf courses in Korea. The disease spread gradually throughout the country and became a threat to turfgrass management. Symptoms of the disease consisted of small, circular, and sunken patches sized 3~5cm in diameter. The disease named as a dollar spot following its characteristic symptoms of circular blight and bleach on the green. The disease peaked two times in a year from April to June and from late August to October and white cottony mycelia of the causal fungus developed on diseased turfs in the early morning when the conditions were favored. A causal fungus was consistently isolated from the infected tufgrass and seven isolates originated from seven golf courses located in six provinces were selected for further study. The fungus produced abundant white aerial mycelia on PDA and turned to dark gray or light brown as it aged. Width of the mycelium was ca. $5~8\mu\textrm{m}$. While sclerotia were not readily formed on the medium, scattered small and dark colored stromata were developed on the surface. The fungus grew well on PDA between 5 to $30^{\circ}C$ and maximally around $25^{\circ}C$. Based on investigated mycological and cultural characteristics, the causal agent of dollar spot was identified as Sclerotinia homoeocarpa. The fungus showed strong pathogenicity to several turfs as creeping bentgrass, Kentucky bluegrass, perennial ryegrass, tall fescues, and zoysiagrass.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.92.2-93
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• 2003

Severe soybean-sprout rot was found at the mass productive factory in 2000 and 2001 and it caused 10-20％ loss of the production. Pythium sp. was isolated almost 90％ by potato dextrose agar from rotted root and hypocotylsof the sprouts. And the pathogencity tests using test tubes with 2％ water agar and small containers (30 ${\times}$ 30 ${\times}$ 50 cm, WxLxH) cultivation were shown a similar rot on roots and hypocotyls. The fungal mycelium grew rapidly on the water agar and it prevented the seed germination. Density of the Pythium sp. in the recycled water system at the factory was periodically measured using a selective medium, corn meal agar with Pimaricin 10 mg, Rifampicin 10 mg, Ampicillin 100 mg per 1 liter in order to check the contamination of recycled water. After fitering step using 5 and 1 ml in the recycled system was applied and it was effectively controlled Pythium rot. The daily yield of sprout was stable and the occurrenceof Pythium in the recycled water was much less after filtering. The fungal isolates were identified as Pythium deliense Meurs based on various mycological characteristics on corn meal agar and sucrose-asparagine bentgrass leaf culture medium. P. deliens oogonia were spherical, smooth, 19-23 urn in diameter, and their stalk bending toward antheridia. Antheridia were straw hat-shaped, curred club-shaped, therminal or intercalary, monoclinous, occasionally diclinous, 12∼15 ${\times}$ 8∼11 um, 1(∼2) per oogonium.

• The Plant Pathology Journal
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• 제17권4호
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• pp.231-235
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• 2001

From April to May 1998, Phytophthora rot on pear, which has not been reported in Korea before, became an epidemic in the southeast part of the country under abnormally higher temperature and prolonged rainy days. Average temperature was about $3^{\circ}$ higher than in normal years, and 29 days were rainy during the 2 months in the areas surveyed. Over 1,000 orchards estimated at about 270 ha in 19 cultivation areas were infected by the disease, which occurred on all parts of the tree such as leaves, shoots, branches, stems, and flower clusters. Among 43 isolates collected from various locations and plant parts, 41 were identified as Phytophthora cactorum while 2 were identified as P. cambivora based on their mycological characteristics. The representative isolates revealed strong pathogenicity not only to pear but also to apple and peach. Among 23 pear cultivars tested, 7 were estimated as susceptible, 4 were moderate, and 11 were resistant to the pathogen. Results suggest that Phytophthora disease on pear is a potential threat to pear cultivation when environmental factors are favorable to disease development.

• The Plant Pathology Journal
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• 제17권6호
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• pp.347-349
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• 2001

Black blights attacked the blossom and flower buds of wild chrysanthemum (Chrysanthemum boreale) in the experimental field in Hamyang in 1998. The infection rate of the disease on the plant ranged from 4.0 to 91.8%. The pathogen isolated from the infected flower buds produced numerous conidia in pycnidia. The pycnidia, which were immersed into the petals, emerged through the epidermis by short ostiolate neck. Conidia had 0-3 septate (mostly uniseptate) and were 10-27.5 $\times$5-7.5 ㎛ in size. The fungus produced pseudothecia on potato dextrose agar (PDA), and uniseptate ascospores produced in asci were 10$\times$2.7 ㎛ in size. The pathogen also produced pycnidia and pycnidiospores on PDA after 4 weeks in the dark condition. The conidia produced on PDA were smaller than those from infected plants. Based on the examined mycological characteristics, the fungus was identified as Didymella chrsanthemi.