• Journal of Microbiology
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• v.43 no.3
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• pp.308-312
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• 2005

The global RNA transcription profiles of Bacillus lentimorbus WJ5 under an in vitro co-culture with Colletotrichum gloeosporioides were analyzed in order to study the antagonistic bacteria-fungi interactions. Using a filter membrane system, B. lentimorhus WJ5 was exposed to the spores of C. gloeosporioides at the late exponential stage. The transcription profiles of the B. lentimorhus WJ5, both with and without a challenge from C. gloeosporioides, were analyzed using custom DNA chips containing 2,000 genome fragments. A total of 337 genes were expressed, with 87 and 47 up- and down-regulated, respectively. Of these, 12 genes, which were involved in central carbon metabolisms, and 7 from minor catabolism were relatively highly up-regulated (> 10 fold) and down-regulated (< 0.2 fold), respectively. Nine genes, which were thought to be related to the antifungal activity, were also up-regulated, but their levels were not so high (2.0 - 9.7 folds). From the results, during the early stage of the co-culture of B. lentimorbus WJ5 and C. gloeosporioides, nutrient competition seemed to occur; therefore, the genes from central carbon metabolisms could be up-regulated, while those from minor catabolism could be down-regulated.

• Mycobiology
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• v.45 no.4
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• pp.401-408
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• 2017

Colletotrichum gloeosporioides is an economically important fungal pathogen causing substantial yield losses indifferent host plants. To understand the genetic diversity and molecular epidemiology of this fungus, we have developed a novel, high-resolution multi-locus microsatellite typing (MLMT) method. Bioinformatic analysis of C. gloeosporioides unannotated genome sequence yielded eight potential microsatellite loci, of which five, CG1 $(GT)_n$, CG2 $(GT1)_n$, CG3 $(TC)_n$, CG4 $(CT)_n$, and CG5 $(CT1)_n$ were selected for further study based on their universal amplification potential, reproducibility, and repeat number polymorphism. The selected microsatellites were used to analyze 31 strains of C. gloeosporioides isolated from 20 different host plants from India. All microsatellite loci were found to be polymorphic, and the approximate fragment sizes of microsatellite loci CG1, CG2, CG3, CG4, and CG5 were in ranges of 213-241, 197-227, 231-265, 209-275, and 132-188, respectively. Among the 31 isolates, 55 different genotypes were identified. The Simpson's index of diversity (D) values for the individual locus ranged from 0.79 to 0.92, with the D value of all combined five microsatellite loci being 0.99. Microsatellite data analysis revealed that isolates from Ocimum sanctum, Capsicum annuum (chili pepper), and Mangifera indica (mango) formed distinct clusters, therefore exhibited some level of correlation between certain genotypes and host. The developed MLMT method would be a powerful tool for studying the genetic diversity and any possible genotype-host correlation in C. gloeosporioides.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.34-34
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• 2014

Filamentous fungi of the genus Colletotrichum (teleomorph, Glomerella) are considered major plant pathogens worldwide. Cereals, legumes, vegetables, and fruit trees may be seriously affected by this pathogen (1). Colletotrichum species cause typical disease symptoms known as anthracnoses, characterized by sunken necrotic tissue, where orange conidial masses are produced. Anthracnose appears in both developing and mature plant tissues (2). We investigated disease occurrence in apple orchards from 2013 to 2014 in northern Gyeongbuk province, Korea. Typical anthracnose with advanced symptoms was observed in all apple orchards studied. Of late, static fruit spot symptoms are being observed in apple orchards. A small lesion, which does not expand further and remains static until the harvesting season, is observed at the beginning of fruit growth period. In our study, static symptoms, together with the typical symptoms, were observed on apples. The isolated fungus was tested for pathogenicity on cv. 'Fuji apple' (fully ripe fruits, unripe fruits, and cross-section of fruits) by inoculating the fruits with a conidial suspension ($10^5$ conidia/ml). In apple inoculated with typical anthracnose fungus, the anthracnose symptoms progressed, and dark lesions with salmon-colored masses of conidia were observed on fruit, which were also soft and sunken. However, in apple inoculated with fungi causing static symptoms, the size of the spots did not increase. Interestingly, the shape and size of the conidia and the shape of the appressoria of both types of fungi were found to be similar. The conidia of the two types of fungi were straight and cylindrical, with an obtuse apex. The culture and morphological characteristics of the conidia were similar to those of C. gloeosporioides (5). The conidia of C. gloeosporioides germinate and form appressoria in response to chemical signals such as host surface wax and the fruitripening hormone ethylene (3). In this study, the spores started to germinate 4 h after incubation with an ethephon suspension. Then, the germ tubes began to swell, and subsequently, differentiation into appressoria with dark thick walls was completed by 8 h. In advanced symptoms, fungal spores of virtually all the appressoria formed primary hyphae within 16 h. However, in the static-symptom fungus spores, no primary hyphae formed by 16 h. The two types of isolates exhibited different growth rates on medium containing apple pectin, Na polypectate, or glucose as the sole carbon. Static-symptom fungi had a >10% reduction in growth (apple pectin, 14.9%; Na polypectate, 27.7%; glucose, 10.4%). The fungal isolates were also genetically characterized by sequencing. ITS regions of rDNA, chitin synthase 1 (CHS1), actin (ACT), and ${\beta}$-tubulin (${\beta}t$) were amplified from isolates using primer pairs ITS 1 and ITS 4 (4), CHS-79F and CHS-354R, ACT-512F and ACT-783R, and T1 and ${\beta}t2$ (5), respectively. The resulting sequences showed 100% identity with sequences of C. gloeosporioides at KC493156, and the sequence of the ${\beta}$t gene showed 100% identity with C. gloeosporioides at JX009557.1. Therefore, sequence data from the four loci studied proves that the isolated pathogen is C. gloeosporioides. We also performed random amplified polymorphic DNA-PCR, which showed clearly differentiated subgroups of C. gloeosporioides genotypes. The clustering of these groups was highly related to the symptom types of the individual strains.

• Korean Journal of Agricultural Science
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• v.14 no.1
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• pp.16-25
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• 1987

Colletotrichum acutatum, C. coccodes, C. dematium and C. gloeosporioides were detected in seed samples of red pepper (Capsicum annuum). C. dematium and C. gloeosporioides were the predominant species, maximum seed infection of the species in some samples were 84% and 28%, respectively. C. acutatum and C. coccodes were recorded only in low percentages of 1-2. The blotter method proved more suitable for detecting Colletotricum spp. than the deep freezing blotter or agar plate methods. Plating of seed components showed that C. dematium and C. gloeosporioides were recovered more frequently from seed coat, and decreasing amounts of infection were observed in the endosperm and cotyledon. Seed-borne C. dematium and C. gloeosporioides caused seed rot, damping-off, seedling blight and brown discoloration of cotyledon and hypocotyl when infected seeds were sown in agar of test tube or in soil. Inoculation experiments showed that C. acutatum was pathogenic to red fruit of red pepper and C. coccodes was highly pathogenic to red fruit and weakly pathogenic to leaf of the plant. C. dematium was highly pathogenic to leaf and green fruit and C. gloeosporioides was pathogenic to not only leaf but also green and red fruits. Host range of the four seed-borne species of Colletotrichum was also investigated.

• Mycobiology
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• v.46 no.2
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• pp.92-100
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• 2018

The filamentous Ascomycota Colletotrichum gloeosporioides sensu lato is a fungus that has been reported worldwide as a causal agent of anthracnose disease in avocado and other crops. In Mexico, this species affects fruits from an early stage of development in the orchard until the post-harvest stage. Although fungicides are continuously applied to control Colletotrichum species, pericarp cankers and soft rot mesocarp in fruits are still frequently observed. Considering the lack of a precise description of the causative agent, the aim of the current study was to determine the pathogens involved in this symptomatology. Twenty-four isolates were consistently obtained from the pericarp of avocado fruits cv. "Hass" collected in the central avocado-producing area of Mexico. Morphological features such as colony growth, conidia size, and mycelial appressorium were assessed. Bayesian multilocus phylogenetic analyses were performed using amplified sequences of the internal transcribed spacer region of the nuclear ribosomal DNA; actin, chitin synthase, glyceraldehyde-3-phosphate dehydrogenase partial genes; and APn2-Mat1-2 intergenic spacer and mating type Mat1-2 partial gene from the nine selected isolates. In addition, fruits were inoculated with a conidial suspension and reproducible symptoms confirmed the presence of Colletotrichum fructicola in this area. This pathogenic species can now be added to those previously reported in the country, such as C. acutatum, C. boninense, C. godetiae, C. gloeosporioides, and C. karstii. Disease management programs to reduce the incidence of anthracnose should include C. fructicola to determine its response to fungicides that are routinely applied, considering that the appearance of new species is affecting the commercial quality of the fruits and shifting the original population structure.

• The Plant Pathology Journal
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• v.34 no.6
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• pp.480-489
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• 2018

Bitter rot caused by Colletotrichum species is a common fruit rotting disease of apple and one of the economically important disease in worldwide. In 2015 and 2016, distinct symptoms of bitter rot disease were observed in apple orchards in five regions of South Korea. In the present study, infected apples from these regions were utilized to obtain eighteen isolates of Colletotrichum spp. These isolates were identified and characterized according to their morphological characteristics and nucleotide sequence data of internal transcribed spacer regions and glyceraldehyde-3-phosphate-dehydrogenase. Molecular analyses suggested that the isolates of Colletotrichum causing the bitter rot disease in South Korea belong to 4 species: C. siamense; C. fructicola; C. fioriniae and C. nymphaeae. C. siamense and C. fructicola belonged to Musae Clade of C. gloeosporioides complex species while C. fioriniae and C. nymphaeae belonged to the Clade 3 and Clade 2 of C. acutatum complex species, respectively. Additionally, we also found that the isolates of C. gloeosporioides species-complex were more aggressive than those in the C. acutatum species complex via pathogenicity tests. Taken together, our results suggest that accurate identification of Colletotrichum spp. within each species complex is required for management of bitter rot disease on apple fruit in South Korea.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.272-278
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• 2015

Colletotrichum gloeosporioides is one of the most serious pathogens of persimmon in Korea. In 2013, 67 isolates of C. gloeosporioides were isolated from infected fruits, leaf and twigs of persimmon (Diosprosi kaki) at Sangju, Gyeongsangbukdo and fungal responses against five fungicides (prochloraz manganese complex, tebuconazole, mancozeb+myclobutanil, fluquinconazole+prochloraz, and tebuconazole+tolyfluanid) were evaluated by their growth on the fungicide-medium. All isolates were inhibited mycelium growth on the medium with each recommended application concentration of flied. $EC_{50}$ (${\mu}g/ml$) of tebuconazole was from 0.02 to 1.04 and average was 0.31. $EC_{50}$ (${\mu}g/ml$) of prochloraz manganese complex was 0.02~0.23 average was 0.078. Average $EC_{50}$ values (${\mu}g/ml$) of Fluquinconazole+Prochloraz (FP) was 0.029. On the basis $EC_{50}$ (${\mu}g/ml$), the correlation coefficient (r) between tebuconazole and prochloraz manganese complex, prochloraz manganese complex and FP, tebuconazole and FP were 0.42, 0.44 and 0.27, respectively.

• The Plant Pathology Journal
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• v.24 no.1
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• pp.24-30
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• 2008

Colletotrichum gloeosporioides forms an appressorium, a specialized infection structure, to infect its hosts. Among 400 and 600 culture filtrates from fungi and class Actinomycetes, six methanol extracts (A5005, A5314, A5387, A5560, A5597, and A5598) from the class Actinomycetes significantly inhibited appressorium formation in C. gloeosporioides infecting pepper fruits in a dose-dependent manner, while conidial germination was slightly enhanced. Two (A5005 and A5560) of them also exhibited distinctive inhibitory effect on the disease progress of pepper anthracnose. Water fractions of both culture filtrates also specifically inhibited appressorium formation in C. gloeosporioides and pepper anthracnose disease. Inhibition of appressorium formation by culture filtrate of A5005 was partially restored by the exogenous calcium. This results suggests that chemicals within A5005 extents its biological activity through disturbance of intracellular $Ca^{2+}$ regulation during prepenetration morphogenesis by C. gloeosporioides. Together, cell-based and target-oriented screening system used in this study should be applicable for other plant pathogenic fungi prerequisite appressorium formation to infect their hosts.

• The Plant Pathology Journal
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• v.31 no.3
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• pp.269-277
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• 2015

Anthracnose caused by Colletotrichum gloeosporioides has been destructive during pepper fruit production in outdoor fields in Korea. In vitro antifungal activities of 15 different plant essential oils or its components were evaluated during conidial germination and mycelial growth of C. gloeosporioides. In vitro conidial germination was most drastically inhibited by vapour treatments with carvacrol, cinnamon oil, trans-cinnamaldehyde, citral, p-cymene and linalool. Inhibition of the mycelial growth by indirect vapour treatment with essential oils was also demonstrated compared with untreated control. Carvacrol, cinnamon oil, trans-cinnamaldehyde, citral and eugenol were among the most inhibitory plant essential oils by the indirect antifungal efficacies. Plant protection efficacies of the plant essential oils were demonstrated by reduced lesion diameter on the C. gloeosporioides-inoculated immature green pepper fruits compared to the inoculated control fruits without any plant essential oil treatment. In planta test showed that all plant essential oils tested in this study demonstrated plant protection efficacies against pepper fruit anthracnose with similar levels. Thus, application of different plant essential oils can be used for ecofriendly disease management of anthracnose during pepper fruit production.

• Research in Plant Disease
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• v.13 no.3
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• pp.204-206
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• 2007

In 2006 to 2007, the potential inoculum source of the anthracnose of sweet persimmon caused by Colletotrichum gloeosporioides was surveyed. The infected twigs, buds, dead twigs, petiole, leaves, dropped fruits were collected and tested for their possibility as overwintering inoculum. The detection rates of the pathogen from various parts of sweet persimmon tree were varied. When the collected samples were examined in April. Over than 93.3% of infected twig samples were harbored mycelia of C. gloeosporioides, and 46.7% of infected buds, 36.7% of dead twigs, 23.3% of petioles, and 16.7% of leaves were beared pathogenic fungus. No pathogenic fungus were detecded from healthy twigs and buds. Infected twigs and bud was important overwintering sites and formed conidia actively in next spring. The infected twigs, leaves, petioles, and fruits in growing season produced great number of conidia and caused active dissemination of the anthracnose disease in sweet persimmon. In growing season, all of the infected parts, such as twigs, leaves, petioles, and fruits produced pathogenic fungus.