• Research in Plant Disease
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• v.21 no.1
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• pp.32-35
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• 2015

Anthracnose occurred in bitter gourd grown in Jeongup areas of Korea in 2011. Anthracnose of bitter gourd appeared as dark brown circular spots on naturally infected leaves and fruits. The symptoms of infected leaves and fruits were small brown to dark brown spots and gradually enlarged to larger cylindrical dark brown lesions. The causal fungus of anthracnose isolated from the diseased plants was identified as Colletotrichum gloeosporioides based on the morphological and cultural characteristics and ITS rDNA sequence analysis. All isolates of C. gloeosporioides produced symptoms on the host leaves by artificial inoculation. This is the first report of anthracnose on bitter gourd caused by C. gloeosporioides in Korea.

• The Korean Journal of Mycology
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• v.46 no.4
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• pp.467-477
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• 2018

Colletotrichum circinans, an anthracnose pathogen, causes serious damage to onions worldwide. In this study, specific molecular markers were developed to detect C. circinans accurately and quickly with both conventional and real-time PCR methods. The cirTef-F/cirTef-R and cirTu-F/cirTu-R primer sets, which are specific for C. circinans, were constructed by analyzing $tef-1{\alpha}$ and ${\beta}-tubulin$ genes in the fungus. Using the conventional PCR method, 100 pg and 1 ng of fungal DNA could be detected using the cirTef-F/cirTef-R and cirTu-F/cirTu-R sets, respectively. Using the real-time PCR method, 10 pg and 100 pg of fungal DNA could be detected more sensitively with the cirTef-F/cirTef-R and cirTu-F/cirTu-R sets, respectively. Detection of C. circinans from the artificially infected onion seeds was possible by using both conventional and real-time PCR methods and the developed cirTef-F/cirTef-R primer set. The PCR markers specific for C. circinans developed in this study may enhance the efficiency of fungal pathogen detection in imported vegetables and seeds.

• Journal of Bio-Environment Control
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• v.21 no.2
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• pp.127-133
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• 2012

Inhibition effects on spore germination and mycelia growth for pepper anthracnose fungi (Collectricum acutatum) were investigated in vitro using eco-friendly agricultural materials as well as ecofriendly pesticides. The inhibition effect on mycelia growth of anthracnose fungi is the highest when the anthracnose mycelia were treated with a pesticide (commercial name: Koreayeok) that contains a mixture of Bacillus subtilis and Panibacillus polymyxa, resulting in 100% inhibition of the mycelia growth. Meanwhile, the range of 20~40% inhibition effects on the growth of anthracnose mycelia was observed with other commercial agricultural materials. The significant inhibition effects on spore formation of anthracnose fungus were shown in vitro with two water dispersible pesticides containing sulfur [BTB (100%) and SulfurStar (95.1%)], Koreayeok (95.0%), Borstar (99.0%) containing Bordeaux mixture, and Jihabudea-KM containing Psedomonas spp. (96.1%), respectively. Taken from these in vitro results of inhibiting of the spore germination and mycelia growth together, Koreayeok is the most effective on control of pepper anthracnose disease in vitro. In addition, two water dispersible pesticides containing sulfur (BTB and SulfurStar) and Borstar (99.0%) containing Bordeaux mixture are also significantly applicable to prevent pepper plants from anthracnose disease in vitro. It remains to be determined whether the selected eco-friendly agricultural materials in effective control of anthracnose in vitro can be used to control pepper anthracnose in field.

• Korean journal of applied entomology
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• v.18 no.1 s.38
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• pp.35-41
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• 1979

Four to $17\%$ of the seeds of ginseng (Panax ginseng Meyer) collected from seemingly healthy plants carried Colletotrichum panacicola Nakata et Takimoto whereas the seeds from the plants with anthracnose sympotoms carried $42\%$ of the same fungus. Prevalent organisms isolated other than C. panacicola from seeds of both kinds of plants were Fusarium, Alternaria, Phoma, Trichoderma and others, ana in that order on acidified potato sucrose agar. C. panacicola also was isolated from 18 months old herbarium specimens. The fungus in the infected tissues also survived during the Korean winter months either on the soil surface or in the soil at 10 and 30 em in depth. When conidial suspensions of C. panacicola were inoculated on detached ginseng leaves, anthracnose symptoms occurred from 25 to $35^{\circ}C$. No symptoms occurred at temperatures below $17^{\circ}C$. Direct sunlight increased significantly the number of anthracnose lesions over those obtained in leaves inoculated in darkness or in 400 lux of fluorescent light. The lesions decreased as age of the leaves increased or as the number of conidia applied decreased. Optimum temperature for mycelial growth and conidial formation of C. panacicola was $25^{\circ}C$. Optimum pH for the mycelial growth was at $pH\;2.8\~4.6$ while the most conidial formation occurred at $pH\;5.2\~5.8.$. When fungicides were applied in the field to ginseng plants with a conidial suspension of C. panacicola, the most effective control of the anthracnose disease was by spraying with difolatan, and followed by maneb, zineb, captan and phaltan; Bordeaux mixture and ferbam were significantly less effective but significantly better than the inoculated control plants.

• The Plant Pathology Journal
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• v.38 no.6
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• pp.593-602
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• 2022

Anthracnose, caused by the ascomycete fungus Colletotrichum scovillei, is a destructive disease in pepper. The fungus germinates and develops an infection structure called an appressorium on the plant surface. Several signaling cascades, including cAMP-mediated signaling and mitogen-activated protein kinase (MAPK) cascades, are involved in fungal development and pathogenicity in plant pathogenic fungi, but this has not been well studied in the fruit-infecting fungus C. scovillei. Ste50 is an adaptor protein interacting with multiple upstream components to activate the MAPK cascades. Here, we characterized the CsSTE50 gene of C. scovillei, a homolog of Magnaporthe oryzae MST50 that functions in MAPK cascades, by gene knockout. The knockout mutant ΔCsste50 had pleiotropic phenotypes in development and pathogenicity. Compared with the wild-type, the mutants grew faster and produced more conidia on regular agar but were more sensitive to osmotic stress. On artificial and plant surfaces, the conidia of the mutant showed significantly reduced germination and failed to form appressoria. The mutant was completely non-pathogenic on pepper fruits with or without wounds, indicating that pre-penetration and invasive growth were both defective in the mutant. Our results show that the adaptor protein CsSTE50 plays a role in vegetative growth, conidiation, germination, appressorium formation, and pathogenicity in C. scovillei.

• Research in Plant Disease
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• v.26 no.3
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• pp.190-193
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• 2020

In 2014, Anthracnose symptoms were observed on fruit of pumpkin in Gangneung, Gangwon in Korea. The typical symptoms on fruit surfaces were circular lesions, brown, shriveled with salmon-colored spore masses on the spots. A fungal isolate was obtained from symptomatic on fruit and cultured on potato dextrose agar at 25℃. The color of the upper surface of the colony varied from white to gray with occurrence of salmon-colored conidial masses and was red to violet on the underside. The causal fungus of anthracnose isolated from the diseased fruits was identified as Colletotrichum fioriniae based on mycological characteristics and sequences of the internal transcribed spacer, glyceraldehyde-3-phosphate dehydrogenase, chitin synthase-1 gene, histone H3, actin gene, beta-tubulin gene region. Pathogenicity tests of the isolate were performed on pumpkin fruit by both wound and non-wound inoculation with conidial suspension (1×10⁶ conidia/ml) and incubated at 25℃. Lesions were observed on both wounded and non-wounded fruit of pumpkin after 7 days inoculation in only C. fioriniae. The pathogen was re-isolated from the lesions of inoculated fruits. To our knowledge, this is the first report of anthracnose on fruit of pumpkin caused by C. fioriniae in Korea.

• The Korean Journal of Mycology
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• v.25 no.1 s.80
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• pp.30-34
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• 1997

Glomerella cingulata (conidial state: Colletotrichum gloeosporioides) was identified as the causal organism of anthracnose of citrus on the basis of morphological characteristics of the conidial state of the fungus isolated from infected leaves of Satsuma mandarin and its ascigerous state isolated from diseased twigs. The pathogen infected the leaves of Satsuma mandarin, citron and Natsu daidai only by wound inoculation. The optimum temperature range for mycelial growth and sporulation of conidia of the strain was $25{\sim}30^{\circ}C$, respectively. The characteristics of anthracnose strain of Satsuma mandarin such as growth rate and color of colony, shape and size of conidia, and appressoria were similar to those of FGG strain. However, the strain isolated from infected leaves and twigs of Satsuma mandarin was different from FGG strain to cause postharvest anthracnose of citrus, because some of morphological and pathological characteristics of the strain isolated did not correspond to those of FGG strain.

• Research in Plant Disease
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• v.8 no.2
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• pp.120-123
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• 2002

Occurrence of anthracnose on red pepper fruit was examined at 6 red pepper-growing regions including Yecheon, Andong, Euisong, Cheongsong, and Ponghwa in Kyungbuk province, Korea in 1999. The disease occurred firstly June 13 at Cheongsong, progressed gradually thereafteri and increased rapidly from late August. The average disease incidence with mid September was 30.4%. There was no significant difference in disease incidence among the regions examined. Correlation coefficient analysis of the disease incidence with weather factors revealed that it was significantly related to relative humidity, precipitation, rainy days, and duration of continuous rainy days. Most fungal isolates from the diseased fruit were Colletotichum gloeosporioides. In the in field experiment, unmature fruit was somewhat more susceptible to the disease than mature fruit. In the field experiment, the disease occurred severely in open fields, having the disease incidence of 12.1%; however, no disease was observed in the rain-proof fields. The anthracnose on red pepper fruit developed earlier and more severely in the successive cropping field with red pepper than the field having other crops. Removal of infected plant debris also delayed and reduced the disease occurrence, suggesting that plant debris infested with the anthracnose fungus serve as a primary inoculum source which may govern the severity of the disease in the field.

• The Plant Pathology Journal
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• v.37 no.6
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• pp.607-618
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• 2021

The pepper anthracnose fungus, Colletotrichum scovillei, causes severe losses of pepper fruit production in the tropical and temperate zones. RAC1 is a highly conserved small GTP-binding protein in the Rho GT-Pase family. This protein has been demonstrated to play a role in fungal development, and pathogenicity in several plant pathogenic fungi. However, the functional roles of RAC1 are not characterized in C. scovillei causing anthracnose on pepper fruits. Here, we generated a deletion mutant (𝜟Csrac1) via homologous recombination to investigate the functional roles of CsRAC1. The 𝜟Csrac1 showed pleiotropic defects in fungal growth and developments, including vegetative growth, conidiogenesis, conidial germination and appressorium formation, compared to wild-type. Although 𝜟Csrac1 was able to develop appressoria, it failed to differentiate appressorium pegs. However, 𝜟Csrac1 still caused anthracnose disease with significantly reduced rate on wounded pepper fruits. Further analyses revealed that 𝜟Csrac1 was defective in tolerance to oxidative stress and suppression of host-defense genes. Taken together, our results suggest that CsRAC1 plays essential roles in fungal development and pathogenicity in C. scovilleipepper fruit pathosystem.

• 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.