• Korean Journal Plant Pathology
• /
• v.11 no.3
• /
• pp.197-209
• /
• 1995

This paper is a third report about the new fungal diseases of economic resource plants in Korea. It contains short descriptions on symptoms, occurrence conditions, pathogen, and some phytopathological notes for each of 10 fungal plant diseases. They are angular leaf spot of Achyranthes japonica by Cercospora achyranthis causing leaf spot and defoliation in the shade of plants, leaf spot of Armoracia lapathifolia by Cercospora armoraciae causing leaf spot to blight from the rainy season to autumn, hypophyllous mold of Dioscorea tokoro by Distocercospora pachyderma causing leaf spot and yellowing, hypophyllous mold of Artemisia spp.by Mycovellosiella ferruginea causing leaf spot and yellowing, angular leaf spot of Aralia elata by Pseudocercospora araliae causing velvety leaf spot and defoliation, hypophyllous mold of Lycium chinense by Pseudocercospora chengtuensis causing velvety leaf spot and defoliation from the rainy season to autumn, angular leaf spot of Diospyros lotus by Pseudocercospora disospyri-morrisianae causing leaf spot and defoliation from summer to autumn, brown leaf spot of Impatiens textori by Pseudocercospora nojimae causing leaf spot to blight from the rainy season, leaf spot of Cephalonoplos segetum by Ramularia cirsii causing leaf spot to blight throughout the growing season, and white mold of Leonurus sibiricus by Ramularia leonuri causing leaf spot to blight mostly in autumn.

• Korean Journal Plant Pathology
• /
• v.10 no.3
• /
• pp.181-191
• /
• 1994

Occurrence of diseases in economic resource plants in Korea is poorly known. This paper reports short descriptions on symptom, occurrence condition, pathogen, and some phytopathological notes for each 10 fungal plant diseases new to Korea; leaf spot of Rosa multiflora with Seimatosporium discosioides causing leaf spot and defoliation, leaf blight of Equisetum arvense with Titaeospora equiseti causing leaf spot to leaf blight, leaf blight of Setaria viridis with Phyrenochaeta setariae causing leaf spot of Aster tataricus with Septoria astericola causing leaf spot and black spot, powdery mildew of Clematis fusca var. coreana with Erysiphe ranunculi causing powdery mildew and dwarfing, powder mildew of Ligularia stenocephala with Erysiphe galeopsidis causing powdery mildew and dwarfing, powdery mildew of Phlox subulata with Erysiphe cichoracearum causing powdery mildew and defoliation tar spot of Lonicera japonica with Rhytisma lonicericola causing tar spot and dwarfing, white rust of Pharbitis nil with Albugo ipomoeae-pandulatae causing white rust and deformation, and white rust of Achyranthes japonica with Albugo achyranthis causing white rust and defoliation.

• Mycobiology
• /
• v.48 no.1
• /
• pp.70-74
• /
• 2020

Sinowilsonia henryi is a rare and endangered plant, as well as an endemic species in China. In July 2018, leaf spot and blight disease was observed on S. henryi in Yichang, Hubei, China. A fungus isolated from disease tissues was identified as Gonatobotryum apiculatum based on morphology and sequence analyses of ITS and LSU regions. Phylogenetic analyses indicated that the species belongs to Dothioraceae (Dothideales). Morphologically, the species produced two distinct types of conidia from authentic media, both conidia were described here. Pathogenicity tests showed that the fungus is a pathogen causing leaf spots on S. henryi. This is the first report of leaf spot and blight disease on S. henryi caused by G. apiculatum in China.

• The Plant Pathology Journal
• /
• v.17 no.5
• /
• pp.249-256
• /
• 2001

Xanthomonas axonopodis pv. glycines 8ra produces a bacteriocin called glycinecinA, which specifically inhibits the growth of bacteria belonging to Xanthomonas species. GlycinecinA was produced by culturing Escherichia coli DH5 containing biosynthetic genes for glycinecinA, and was tested for its control effect against X. vesicatoria on red pepper and X. oryzae pv. oryzae on rice. The bacteriocin activity was much higher in the cell extract than in the supernatant. It reached a maximum level at the stationary phase, ws maintained up to 2 months at room temperature and approximately 10 months at $4^{\circ}$. The optimum concentration of glycinecinA for the control in the greenhouse and in the field was 12,800 AU/ml. In this study, the activity of glycinecinA on rice and red pepper leaves continued for 7-8 days, during which the pathogen populations remained at low levels. Bacterial leaf spot of red pepper and bacterial leaf blight of rice were significantly reduced by the bacteriocin treatments. The control efficacy was as high as, or even higher than, the chemical treatment of copper hydroxide. These results suggest that the bacteriocin is a potential control agent for bacterial diseases.

• The Plant Pathology Journal
• /
• v.37 no.4
• /
• pp.329-338
• /
• 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.

• The Plant Pathology Journal
• /
• v.33 no.4
• /
• pp.434-439
• /
• 2017

Incidence rates of diseases in kiwiberry orchards were investigated monthly from late June to late September in Gwangyang and Boseong in 2015 and 2016. The impact of postharvest fruit rot was investigated during ripening after harvest. Bacterial canker was only observed on one single tree in 2015, but black rot, powdery mildew, leaf spot and blight, and postharvest fruit rot diseases were problematic throughout the study period in both 2015 and 2016. Incidence rates of the diseases varied with kiwiberry cultivar, region and sampling time. Incidence rates of powdery mildew, leaf spot and blight diseases increased significantly during the late growing stages near fruit harvest, while black rot peaked in late August. Incidence rate of postharvest fruit rot on fruit without fruit stalks was less than half of fruit with fruit stalks, regardless of kiwiberry cultivars. Among the four cultivars, Mansu was relatively resistant to black rot and postharvest fruit rot diseases. In our knowledge, this is the first report of various potential pathogens of kiwiberry in Korea.

• Mycobiology
• /
• v.38 no.4
• /
• pp.316-320
• /
• 2010

Leaf spot and blight disease was observed on two-year-old seedlings of Dendropanax morbifera (Korean name: Hwangchil tree) during July of 2008 in Jindo Island, Korea. Symptoms included yellow-brown to dark brown irregularly enlarged spots frequently located along the veins of leaves. The lesions were often surrounded by chlorotic haloes. Severe leaf blight and subsequent defoliation occurred when conditions favored disease outbreak. The causal organism of the disease was identified as Alternaria panax based on morphological characteristics and sequence analysis of the internal transcribed spacer region of rDNA. A. panax isolates induced leaf spots and blight symptoms not only on D. morbifera but also on the other members of Araliaceae tested. This is the first report of foliar blight caused by A. panax on D. morbifera.

• Journal of Sericultural and Entomological Science
• /
• v.37 no.1
• /
• pp.86-91
• /
• 1995

Isolation and pathogenicity of Fusarium spp. from mulberry shoot rot and severity of diseases which were known as bacterial blight were examined on four mulberry varieties in Suwon, Kongju and Chuncheon, A symptom of mulberry shoot rot was initiated long brown spot on young leaves and shoots. It was developed into dark brown spot and produced white mycelia and spores on the diseased symptoms. A symptom of bacterial blight showed leaf rolling and water soaking spot and produced bacterial ooze on leaf and shoot However later stage of upper two types of symptom was hardly distinguished. Severities of shoot rot and bacterial blight were 7.5% and 4.4% in Suwon, respectively. Isolation of Fusarium spp. on shoot rot symptoms was highter than that on bacterial blight symptoms, but isolation of Pseudomonas spp. was higher on bacterial blight symptoms. Trends of pathogenicity of Fusarium spp. and Pseudomonas spp. were similar to inoculation works, and isolations of pathogenic Fusarium spp. from center of symptom was higher than that from 30cm of symptom of all samples in three cultivation areas. Disease severities of shoot rot on variety of Kaeryangppong were 13.9%, 15.9% and 17.2% in Suwon, Kongju and Chuncheon, respectively. However variety of Cheongolppong was highly resistant to shoot rot disease in three cultivation areas.

• The Plant Pathology Journal
• /
• v.16 no.5
• /
• pp.280-282
• /
• 2000

A leaf spot disease occurred on Allium tuberosum Roth. (Chinese chive) in Korea. All the isolates of Stemphylium sp. from the lesions of the diseased plant parts were identified as S. vesicarium (Waller.) Simmons, based on the morphological characteristics of conidia and conidiophores. Pathogenicity of the fungus was proved by artificial inoculation on Chinese chive plants. This is the first record of leaf blight on Chinese chive caused by S. vesicarium in Korea.

• Mycobiology
• /
• v.46 no.3
• /
• pp.278-282
• /
• 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.