• The Plant Pathology Journal
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• v.27 no.2
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• pp.156-163
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• 2011

Antifungal activity of three Myxococcus spp., KYC 1126, 1136, and 2001, was tested in vitro against three phytopathogenic fungi (Botrytis cinerea, Colletotrichum acutatum, and Pyricularia grisea). Spore germination and mycelial growth of the three pathogenic fungi were completely inhibited by bioactive substances from a myxobacterium KYC 1126. In addition, the activity of KYC 1126 was fungicidal, but liquid culture filtrate of KYC 1126 did not affect protoplast reversion in C. acutatum. A bioassay of KYC 1126 filtrate against anthracnose in hot pepper was conducted in the greenhouse and field at 2009 and 2010. The incidence of anthracnose in control seedlings was 74%, but was reduced to 29% after KYC 1126 treatment. The control value with KYC 1126 was 60% while that with the fungicide dithianon was 42%. In the greenhouse, disease incidence with KYC 1126 was consistentely 10-35% lower than with fungicide as a positive control. The control value with KYC 1126 was 13.4% and 41.0%, whereas that with the fungicide was 52.3% and 63% in 2009 and 2010, respectively. Although anti-anthracnose activity of KYC 1126 was not maintained for long time in the field, the bacteriolytic myxobacterium KYC 1126 could be a prospective biocontrol agent.

• The Plant Pathology Journal
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• v.26 no.3
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• pp.273-279
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• 2010

We evaluated 209 Capsicum accessions from the National Agrobiodiversity of RDA, for their reaction against of anthracnose disease caused by Colletotrichum acutatum. Two hundred nine accessions of Capsicum were almost composed with Capsicum annuum var. annuum originated from 37 countries. The percentage of infection due to C. acutatum ranged from 11.1% to 100% on immature and matured pepper fruits at 21 days after inoculation. On immature fruits of pepper, one hundred seventy three accessions of tested pepper were found infected with C. acutatum. Out of the 173 accessions, eighty five accessions were susceptible to anthracnose with dark brown to black lesions and slowly increased in size at 21 days after inoculation. Only thirty six accessions showed resistance against C. acutatum. On mature fruits of pepper, one hundred ninety eight accessions were infected with C. acutatum at 21 days after inoculation. Twenty one accessions showed a resistance reaction against C. acutatum. The results of this work indicated that all of resistance accessions to C. acutatum were have a genetic potential for the resources of resistance can be further used in pepper breeding programme against anthracnose and also demand more detailed investigation in this.

• Journal of Microbiology and Biotechnology
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• v.16 no.2
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• pp.280-285
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• 2006

Methanol extract of the rhizomes of turmeric, Curcuma longa L., effectively controlled the development of red pepper anthracnose caused by Colletotrichum coccodes. In addition three antifungal substances were identified from the methanol extract of C. longa rhizomes as curcumin, demethoxycurcumin, and bisdemethoxycurcumin using mass and $^{1}H-NMR$ spectral analyses. The curcuminoids in a range $0.4-100\;{\mu}g/ml$ effectively inhibited the mycelial growth of three red pepper anthracnose pathogens, C. coccodes, C. gloeosporioides, and C. acutatum. The three curcuminoids inhibited mycelial growth of C. coccodes and C. gloeosporioides to an extent similar to the synthetic fungicide dithianon did, but the synthetic agent was a little more effective against C. acutatum. The curcuminoids also effectively inhibited spore germination of C. coccodes, and bisdemethoxycurcumin was the most active. Among the three curcuminoids, only demethoxycurcumin was effective in a greenhouse test in suppressing red pepper anthracnose caused by C. coccodes.

• The Plant Pathology Journal
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• v.31 no.2
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• pp.165-175
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• 2015

Anthracnose is a fungal disease caused by Colletotrichum species that is detrimental to numerous plant species. Anthracnose control with fungicides has both human health and environmental safety implications. Despite increasing public concerns, fungicide use will continue in the absence of viable alternatives. There have been relatively less efforts to search antagonistic bacteria from mudflats harboring microbial diversity. A total of 420 bacterial strains were isolated from mudflats near the western sea of South Korea. Five bacterial strains, LB01, LB14, HM03, HM17, and LB15, were characterized as having antifungal properties in the presence of C. acutatum and C. gloeosporioides. The three Bacillus atrophaeus strains, LB14, HM03, and HM17, produced large quantities of chitinase and protease enzymes, whereas the B. amyloliquefaciens strain LB01 produced protease and cellulase enzymes. Two important antagonistic traits, siderophore production and solubilization of insoluble phosphate, were observed in the three B. atrophaeus strains. Analyses of disease suppression revealed that LB14 was most effective for suppressing the incidence of anthracnose symptoms on pepper fruits. LB14 produced antagonistic compounds and suppressed conidial germination of C. acutatum and C. gloeosporioides. The results from the present study will provide a basis for developing a reliable alternative to fungicides for anthracnose control.

• Journal of Life Science
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• v.27 no.6
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• pp.688-693
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• 2017

Antifungal bacterium against Colletotrichum coccodes causing black dot disease of potatoes and anthracnose of tomatoes was isolated from sewage sludge. The isolate showed a 99% sequence homology of partial 16S rRNA of Bacillus methylotrophicus CBMB205 and Bacillus amyloliquefaciens subsp. plantarum FZB42. The isolate was identified as Bacillus sp. SW29-2, using the neighbor-joining phylogenetic tree, BlastN sequence analysis, and morphological and cultural characteristics. Bacillus sp. SW29-2 is an aerobic, Gram-positive, endospore-forming bacterium, of which the morphological and physiological characteristics were the same as those of type strain B. lichniformis CBMB205, except for the cell growth of over 4% NaCl. The cell growth of the temperature and the initial pH of the medium was shown at $18-47^{\circ}C$ (opt. ca. $38^{\circ}C$) and 3-9 (opt. ca. 6.0), respectively. The inhibition size (diameter) of Bacillus sp. SW29-2 against four strains of C. coccodes ranged from 23 to 29 mm. Also, the isolate showed antifungal activity against penicillium rot-causing Penicillium expansum in apples. Thus far, any report on the antifungal activity of Baciilus spp. against C. coccodes has not been found. These results suggest that the Bacillus sp. SW29-2 isolate could be used as a possible biocontrol agent against C. coccodes, and further applied to other plant pathogenic fungi.

• Research in Plant Disease
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• v.8 no.4
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• pp.239-244
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• 2002

Among 34 isolates of Colletotrichum spp., 20 from red pepper and 14 from apple, only one isolate 2001-45 was identified as the isolate resistant to sterol biosynthesis inhibiting fungicides. EC$_{50}$ values of the isolate 2001-45 were 153.5, 42.7, 34.0, and 17.1 $\mu\textrm{g}$/ml for myclobutanil, tebuconazole, hexaconazole and nuarimol, respectively, The resistance factor of the isolate 2001-45 against the other isolate 2001-44 to 4 above fungicides was ranged from 17 to 57. However, EC$_{50}$ value of the 2001-45 for prochloraz was 0.07 $\mu\textrm{g}$/ml, which was lower than those of the 2001-44 and the isolate JC24. For the fitness test of the 2001-45, mycelial growth, sporulation on PDA and pathogenicity on fruits were investigated. No difference in mycelial growth was found between 2001-45 and 2001-44, but great difference in sporulation. No symptom was developed by 2001-45 even by wound inoculation of pepper fruit. Therefore, this study indicated that the isolate 2001-45 was inferior to the other isolates in the fitness, although the isolate 2001-45 was highly resistant to sterol biosynthesis inhibiting fungicides.

• Research in Plant Disease
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• v.18 no.2
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• pp.93-100
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• 2012

Resistance of pepper (Capsicum spp.) to anthracnose (Colletotrichum acutatum) was evaluated during regeneration of Capsicum spp. in National Agrobiodiversity Center. Disease severity of 896 pepper accessions (430 accessions of C. annuum, 219 accessions of C. baccatum, 14 accessions of C. chacoense, 153 accessions of C. chinense, 70 accessions of C. frutescens, 2 accessions of C. pubescens, and unidentified 8 accessions) was investigated at 14 days after inoculation in $28^{\circ}C$ humid chamber. Forty nine accessions of pepper germplasm were resistant to C. acutatum. Among them, nine accessions were highly resistant to C. acutatum without wounding spray inoculation. Four accessions belonged to the species C. baccatum, one accession to C. chacoense, and four accessions to C. frutescens. Forty two resistant candidate accessions were inoculated with pin-prick wounding using a syringe needle. Five accessions were resistant as a less than 3% of disease severity to C. acutatum with wounding inoculation 5 days after inoculation. All resistant accessions were C. baccatum. These five pepper germplasm might be used as breeding resources for the anthracnose resistance breeding program.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.335-344
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• 2015

It was conducted to identify all 47 isolates obtained from infected fruits of pepper and boxthorn, and to investigate the mycological characteristics and the response to fungicides. All of 11 isolates from pepper were identified as Colletotrichum acutatum included into A2 group. Among 36 isolates from boxthorn, 14 isolates were identified as C. gloeosporioides, and the others were done as C. acutatum, which were composed as A1 group with 15 isolates and A3 with 7 isolates. After incubating the isolates on PDA at $25^{\circ}C$ for 10 days, the colony color of C. acutatum was greyish white, while that of C. gloeosporioides was orange at center of colony and was gradually turned into an greyish white to the periphery. The rate of conidia showing ellongated ellipsoidal shape with round ends was over 95% in C. acutatum isolated from pepper. However, C. acutatum isolated from boxthorn produced ellongated ellipsoidal conidia with the rate of 75%, and the others were pointed at one or both ends. Regardless of species of Colletotrichum, all isolated used in this study was showed an optimal temperature at $25^{\circ}C$. $EC_{50}$ values of all isolates of Colletotrichum spp. to 2 fungicides as carbendazim and the mixture of carbendazim and diethofencarb was investigated by an agar dilution method. With C. acutatum isolates from pepper belonged to A2 group, the mean of $EC_{50}$ value to carbendazim and the mixture of carbendazim and diethofencarb was 0.68 and $3.16{\mu}g/ml$, respectively. In the case of C. acutatum isolates from boxthorn, which were divided into 2 groups as A1 and A3 group, that to carbendazim was 0.21 at A1 and $0.24{\mu}g/ml$ at A3, while that to the mixture was 1.52 and $3.35{\mu}g/ml$. Isolates of C. gloeosporioides showed the mean of $EC_{50}$ value was $0.12{\mu}g/ml$ to carbendazim and $0.92{\mu}g/ml$ to the mixture. The value of resistant factor was higher in the isolates of C. acutatum obtained in boxthorn than those from pepper.

• Research in Plant Disease
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• v.13 no.2
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• pp.93-97
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• 2007

The microorganisms with the antifungal activity against Phytophthora capsici and Colletotrichum acutatum and the plant growth promotion activity were screened from forest soils of Moon-gyeong (Juheul Mountain), Gyeongsangbuk-do. One of the isolates, strain MG 121 showed antifungal activity against P. capsici and C. acutatum and possessed phosphate solubilization activity was selected to development biocontrol agent. The strain MG 121 was identified as Streptomyces sp. by analysis of 16S rDNA. On the test with pepper fruits, the strain inhibited disease incidences of late blight and anthracnose over 80%. In greenhouse test, plant height, the number of leaf, fresh weight and roots length of pepper plants upon treatment of culture suspension of Streptomyces sp. MG 121 were significantly higher than those without the bacterial cells. In addition, strain MG 121 was capable to solublize rock-phosphate after incubation for 144 hours in potato dextrose broth. The concentration of soluble phosphate in PDB amended with 0.5% rock-phosphate was increased up to $765{\mu}g/ml$.

• Horticultural Science & Technology
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• v.28 no.6
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• pp.1014-1024
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• 2010

Pepper ($Capsicum$ spp.) anthracnose caused by $Colletotrichum$ $acutatum$ is a destructive disease susceptible to areas where chili peppers are grown. $Capsicum$ $baccatum$ var. $pendulum$ (Cbp) is resistant to anthracnose and has actively been used for interspecific hybridization for the introgression of resistance gene(s) into cultivated chili peppers. The goals of this study were to determine the inheritance of resistance to anthracnose within $Capsicum$ $baccatum$ and to map quantitative trait loci (QTLs) for the anthracnose resistance. A genetic mapping population consisting of 126 $F_2$ plants derived from a cross between $Capsicum$ $baccatum$ var. $pendulum$ (resistant) and $Capsicum$ $baccatum$ 'Golden-aji' (susceptible) was used for linkage mapping. The linkage map was constructed with 52 SSRs, 175 AFLPs, and 100 SRAPs covering 1,896cM, with an average interval marker distance of 4.0cM. Based on this map, the number, location, and effect of QTLs for anthracnose resistance were studied using plants inoculated in the laboratory and field. A total of 19 quantitative trait loci (2 major QTLs and 16 minor QTLs) were detected. Two QTLs ($An8.1$, $An9.1$) showed 16.4% phenotypic variations for anthracnose resistance after wounding inoculation. In addition, five minor QTL loci ($An7.3$, $An7.4$, $An4.1$, $An3.1$, $An3.2$) showed a total of 60.73% phenotypic variations of anthracnose resistance in the field test. Several significant QTLs were also detected and their reproducibility was confirmed under different inoculation conditions. These QTLs are now being confirmed with different breeding populations. Markers tightly linked to the QTLs that are reliable under different environmental conditions will help to determine the success of marker-assisted selection for anthracnose -resistant breeding programs in chili pepper.