• 한국식물병리학회지
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• 제11권3호
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• pp.210-216
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• 1995

Alternaria spp.were predominantly isolated from the abnormal leaf spot lesions of pear cultivars Niitaka and Nijiiseiki. Alternaria isolates from the cultivar Niitaka were not pathogenic to both cultivars, but the isolates from the cultivar Nijiiseiki developed typical lesions of black leaf spots and were identified as A. kikuchiana. However, no typical abnormal leaf spot lesions were produced by the Alternaria isolates. Foliar spray of twelve different agrochemicals including lime sulfur, either alone or in combinations, with 7 times applications from April to July failed to reduced the disease development. Application of 17 different pesticides including fungicides, insecticides and herbicides currently used in pear orchards did not cause leaf injury similar to the abnormal leaf spot. Simulated acid rain of as low as pH 3.0 did not incite any leaf lesions alike the abnormal spot lesions. Mineral contents in the leaves of both cultivars did not differ significantly between the healthy leaves and those with abnormal leaf spots. When cuttings of pear tree were obtained in February from newly emerged twigs of the healthy or the diseased trees of Niitaka and planted in sand in the greenhouse, only those from the diseased trees developed typical leaf lesions of the abnormal spot. These results indicate that abnormal leaf spots are caused by unknown systemic agents in pear trees, rather than by Alternaria spp., chemical injury or acid rain.

• Mycobiology
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• 제42권4호
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• pp.405-408
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• 2014

Leaf spot disease was observed in sesame (Sesamum indicum L.) during 2009 and 2010 in Korea. The pathogen was identified as Alternaria simsimi based on morphological and cultural characteristics. The morphological identification was well supported by phylogenetic analysis of the ribosomal DNA-internal transcribed spacer region. A. simsimi isolates caused spot symptoms on leaves and stems of sesame plants 2 wk after artificial inoculation, which were similar to those observed in the field. This is the first record of leaf spot disease in Korea caused by A. simsimi.

• 식물병연구
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• 제10권2호
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• pp.126-129
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• 2004

2002년 7월 전북지방에 야생하는 칡의 잎에 점무늬병이 발병하였다. 잎에 처음에는 작은 점무늬증상이 나타나고. 이 점무늬 주변에 황색의 halo가 형성되는 것이 전형적인 특징이었다. 병반들이 점차 확대되어 융합되어 잎 전체가 황색으로 변색되며 결국 낙엽이 된다. 병원균이 분리되었으며 본 병원균의 균사집락은 PDA 배지에서 밝은 회녹색에서 암갈색이었다. 분생포자는 대부분 단생이며 드물게 3-8개 포자가 연쇄상으로 형성되었다. 분생포자는 암갈색이며 긴 난형 또는 곤봉형이고 크기는 20-60${\times}$10-25 $\mu\textrm{m}$이었다. 격막은 4-8개의 횡격막과 1-2개의 종격막을 형성하였다. 칡의 잎에 발생한 병징과 본 병원균의 균학적 특징을 검정한 결과, 이 병을 Alternaria tenuissima에 의한 칡 점무늬병으로 명명하고자 제안한다.

• 식물병연구
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• 제21권4호
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• pp.330-333
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• 2015

In June 2013, we collected leaf spot disease samples of Datura metel from Gangneung, Gangwon Province, Korea. The symptoms observed were small circular to oval dark brown spots with irregular in shape or remained circular with concentric rings. We isolated the pathogen from infected leaves and cultured the fungus on potato dextrose agar. We examined the fungus morphologically and confirmed its pathogenicity according to Koch's postulates. The results of morphological examinations, pathogenicity tests, and the rDNA sequences of the internal transcribed spacer regions (ITS1 and ITS4), glycerol-3-phosphate dehydrogenase (G3PDH) and the RNA polymerase II second largest subunit (RPB2) gene sequence revealed that the causal agent was Alternaria tenuissima. To the best of our knowledge, this is the first report of leaf spot of D. metel caused by A. tenuissima in Korea as well as worldwide.

• Mycobiology
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• 제46권3호
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• pp.278-282
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• 2018

Chrysanthemum coronarium is an economically important plant in Asia, and used medicinally, ornamentally and as a vegetable. In April 2017, leaf spot disease on C. coronarium was observed in Shiyan, Hubei, China. A single-spore isolate was obtained and identified based on morphology and sequence analysis using four regions (rDNA ITS, GAPDH, $EF-1{\alpha}$, and RPB2). The results indicated that the fungus is Alternaria argyranthemi. The pathogenicity tests revealed that the species could cause severe leaf spot and blight disease on the host. This is the first report of leaf spot disease on C. coronarium caused by A. argyranthemi in the world, which is also a new record of Alternaria species in China.

• 식물병연구
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• 제27권3호
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• pp.107-114
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• 2021

During a disease survey on weeds and minor cultivated crops in Korea, a brown leaf spot disease was observed on Sonchus asper. Leaf lesions were round or irregular in shape, and grayish brown to brown with a purple margin. In severe infection, lesions enlarged and coalesced, resulting in blighting of the leaves. The isolates from these leaf lesions were identified as Alternaira sonchi based on morphological characteristics and phylogenetic analyses of Internal transcribed spacer region, Alternaria allergen a1, glyceraldehyde 3-phosphate dehydrogenase, RNA polymerase II, and translation elongation factor genes. This study provides a comprehensive description of the morphological characteristics and phylogenetical traits of A. sonchi causing brown leaf spot on S. asper in Korea.

• The Plant Pathology Journal
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• 제37권4호
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• pp.329-338
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• 2021

Alternaria leaf blight is one of the most common diseases in watermelon worldwide. In Korea, however, the Alternaria species causing the watermelon leaf blight have not been investigated thoroughly. A total of 16 Alternaria isolates was recovered from diseased watermelon leaves with leaf blight symptoms, which were collected from 14 fields in Korea. Analysis of internal transcribed spacer (ITS) region, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and RNA polymerase II second largest subunit (RPB2) were not competent to differentiate the Alternaria isolates. On the contrary, analysis of amplicon size of the histone H3 (HIS3) gene successfully differentiated the isolates into three Alternaria subgroups, and further sequence analysis of them identified three Alternaria spp. Alternaria tenuissima, A. gaisen, and A. alternata. Representative Alternaria isolates from three species induced dark brown leaf spot lesions on detached watermelon leaves, indicating that A. tenuissima, A. gaisen, and A. alternata are all causal agents of Alternaria leaf blight. Our results indicate that the Alternaria species associated watermelon leaf blight in Korea is more complex than reported previously. This is the first report regarding the population structure of Alternaria species causing watermelon leaf blight in Korea.

• Mycobiology
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• 제44권3호
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• pp.187-190
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• 2016

In July 2015, diseased leaves of black chokeberry (Aronia melanocarpa) were observed in Danyang and Gochang, Korea. The symptoms appeared as circular or irregular brown leaf spots, from which Alternaria tenuissima was isolated. The isolates were cultured on potato dextrose agar, and their morphological characteristics were observed under a light microscope. The colonies were whitish to ash colored. The pathogenicity test on healthy black chokeberry leaves produced circular brown spots, in line with the original symptoms. Molecular analyses of the ITS, GPD, RPB2, and TEF genes were conducted to confirm the identity of the pathogen. The phylogeny of the multi-gene sequences indicated that the causal agent was A. tenuissima. This study is the first report of A. tenuissima leaf spot on black chokeberry (A. melanocarpa).

• 식물병연구
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• 제9권3호
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• pp.159-161
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• 2003

잇꽃 잎점무늬병이 2000년 경북 의성군 일대의 잇꽃재배농가포장에서 발생하였다. 조사지역의 발병엽율은 30% 내외였다. 병징은 발아 후에 떡잎에 갈색의 반점을 만들어 완전히 전개하지 못하여 갈변하여 갈라지는 증상과 생육중기이후 잎에 갈색의 반점과 주위에 노랗게 탈색되는 병징이 생기고 이후 중앙부위는 회색 또는 검은 색으로 확대되면서 주위의 노란 변색부위도 확대되었고, 심해지면 전체가 갈색으로 고사하여 낙엽 되었다. Alternaria alternata의 균학적 특징은 분생자경의 길이는 20~110${\mu}m$; 포자의 크기가 10~20 ${\times}$ 30~60 ${\mu}m$이었으며, 격벽수는 3~8개; beak의 길이는 5~35 ${\mu}m$로 짧은 형태의 포자가 연쇄상으로 붙어 있었다. A.carthami는 분생자경의 길이는 40~80${\mu}m$; 포자의 크기가 10~15 ${\times}$40~100 ${\mu}m$ 이었으며, 격벽수는 4~10개; beak의 길이는 30~65 ${\mu}m$로 대부분의 포자는 하나씩 분리되어 있었다. 잇꽃의 점무늬 병징에서 분리한 병원균의 균학적 특징을 Joseph(1994)의 보고와 비교해본 결과 생육중기에 분리된 균은 A. carthami이었으며, 떡잎과 노쇄한 잎의 병반에서 분리한 병원균은 A. alternata로 동정되었다. 그러므로 이 병을 A. carthami와 A. alternata에 의한 잇꽃의 잎점무늬병으로 명명할 것을 제안한다.

• 한국응용곤충학회지
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• 제26권4호
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• pp.273-275
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• 1987

Changes in the numbers of air-borne spores of Alternaria mali causing the Alternaria leaf spot of apple were investigated in apple orchards, by monitoring their AM- toxin(host-specific toxin) producing ability. Most of the air-borne Alternaria in apple orchards were not AM-toxin producers. In culture, only about 2% of Alternaria isolates from a commercially managed apple orchards produced the toxin that was highly toxic only to susceptible leaves.