• Research in Plant Disease
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• v.12 no.3
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• pp.168-177
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• 2006

Thirty-nine strains of Colletotrichum gloeosporioides and 5 strains of C. acutatum stored in Korean Agricultural Culture Collection(KACC) were re-identified based on molecular characteristics of ribosomal internal transcribed spacer(ITS) and partial $\beta$-tubulin gene and cultural characteristics on potato dextrose agar(PDA) and Benomyl-added PDA. As the results, 19 strains were identified as C. acutatum with 13 strains of group A2, 5 strains of group A3, and 1 strain of group A4. In addition, 20 strains were identified as C. gloeosporioides with 18 strains of ribosomal DNA group(RG) 4 and 2 strains of RG6. The rest were identified as C. boninense RG5(2 strains), C. coccodes RG2(2 strains), and C. dematium RG12(1 strain). Out of domestic 31 strains, 12 strains were identified as C. acutatum A2, one strain as C. acutatum A3, 14 strains as C. gloeosporioides RG4, 2 strains as C. gloeosporioides RG6, one strains as C. boninense RG5 and one strain as C. dematium RG12. We also discussed taxonomy of C. gloeosporioides and C. acutatum and composition of C. gloeosporioides/C. acutatum isolates from major crops in Korea.

• Research in Plant Disease
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• v.14 no.3
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• pp.219-222
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• 2008

Real time PCR was used to discriminate Colletotrichum acutatum and C. gloeosporioides for analysis of population density. Two primers, caInt2 and cgint, used for conventional PCR to discriminate two species were modified with fluorescent dye to make probe for real time PCR. Fluorescence signals were successfully detected by fCaInt2 and vCgint probe coupled with primer pair Unicon and Unicor1 resulting in discrimination of C. acutatum and C. gloeosporioides by comparison of delta Rn value.

• Korean Journal Plant Pathology
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• v.10 no.2
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• pp.105-111
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• 1994

Pathogenic fungal species associated with apple anthracnose were studied with diseased fruits collected over two major apple growing areas from 1986 to 1988. Colletotrichum acutatum Simmonds, c. gloeosporioides(Penz.) Sacc. and Glomerella cingulata(Stonem.) Spauld. & Schrenk were identified based on their mycological characteristics. C. acutatum could be easily differentiated from C. gloeosporioides by producing their fusiform conidia and developing apricot∼salmon colony colors, non-forming an ascigerous stages. Growth rate of C. acutatum were slow in plate culture. The three species of anthracnose fungi tested caused apple rot. Symptoms produced by C. gloeosporioides were larger than those of the others. C. gloeosporioides and G. cingulata produced rot lesions on apples that appeared became brown and later black, but C. acutatum produced rot lesions appeared yellowish brown and later reddish brown. G. cingulata has the major species responsible for apple anthracnose, epidemics in Korea.

• The Plant Pathology Journal
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• v.23 no.3
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• pp.187-192
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• 2007

The anthracnose disease on pepper fruits in Korea was caused by Colletotrichum acutatum as well as C. gloeosporioides. Since C. acutatum showed less sensitivity to benomyl, it was analyzed whether the less sensitivity was given by the same mechanism for the fungicide resistance of C. gloeosporioides. The isolates of C. acutatum were less sensitive to the three benzimidazole fungicides tested, benomyl, carbendazim, and thiophanate-methyl. However, the of C. acutatum isolates were different from the resistant isolates of C. gloeosporioides in their response to diethofencarb, one of N-phenyl-carbamates; the former was still less sensitive to diethofencarb than the latter. The differences in the resistance mechanisms in two species were conspicuous in sequence analysis of the tub2 genes. The genes from C. acutatum did not show any non-synonymous base substitutions at the regions known to be correlated with the benzimidazole-resistance. All of these data may indicate that the less sensitivity of C. acutatum to benomyl is based on different mechanism(s) from that of C. gloeosporioides.

• Research in Plant Disease
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• v.11 no.1
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• pp.21-27
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• 2005

It was confirmed that anthracnose pathogen, Colletotrichum acutatum, could specifically grow on PDA amended with $100\mu\textrm{g}$ /ml of ampicillin and tetracycline, and 100 $100\mu\textrm{g}$/ml of mixture with carbendazim and diethofencarb. There was a positive correlation between the number of colony enumerated on semi-selective media and the disease severity on pepper fruits caused by C. acutatum. Using semi-selective media for C. acutatum, the number of pathogen on soil and plant debris infected by anthracnose pathogen was investigated. In plant debris, the colony number of C. acutatum was more than in soil. For the identification of colony appeared on semi-selective media, 10 isolates were selected randomly. They were identified as C. acutatum through PCR using C. acutatum-specific primer.

• Journal of Crop Science and Biotechnology
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• v.10 no.4
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• pp.277-280
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• 2007

Pepper fruit anthracnose, caused by Colletotrichum acutatum, results in serious yield loss and affects crop quality in many Asian countries, making it a disease of economic consequence. A source resistant to C. acutatum was identified by the AVRDC within the line Capsicum chinense Jacq. PBC932. The resistant breeding line C. annuum AR is the $BC_3F_6$ generation derived from C. chinense Jacq. PBC932. The inheritance of resistance to C. acutatum was analyzed in segregating populations derived from the two crosses HN 11$\times$AR and Daepoong-cho$\times$AR. Detached mature green fruits were inoculated using microinjection method. The disease response was evaluated as the disease incidence at 7 DAI. The segregation ratios of resistance and susceptibility to C. acutatum in the $F_2$ and $BC_R$ populations derived from the two crosses fit significantly to a 1:3 Mendelian model. This indicates that the resistance of AR to C. acutatum is controlled by a single recessive gene.

• 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.

• The Korean Journal of Mycology
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• v.21 no.3
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• pp.224-229
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• 1993

The optimum temperature for germination of conidia and germ tube elongation were between $20\;and\;30^{\circ}C$ in C. dematium and C. gloeosporioides. Appressoria were fairly formed well at $20^{\circ}C$ despite the delay of conidial germination. At $30^{\circ}C$, both the germination and germ tube elongation are favored, but appressoria were poorly detected to be formed. In C. acutatum, the optimum temperature for germination of conidia was from $20\;to\;30^{\circ}C$, but at $25^{\circ}C$, germ tube elongation are accelerated. The conidia become septate and one or both doughter cells become conidiogenous instead of producing germ tubes and a secondary conidia produced, resulting in an arborescent type of connected conidia. Appressoria are infrequently formed by germinating conida. At $20\;to\;25^{\circ}C$ was the optimum for appressorium formation. But conidia that germinated at $30^{\circ}C$ seemed to lose the ability to form appressoria. The relation of temperature to germination of conidia and appressorium formation in Colletotrichum acutatum, C. dematium and C. gloeosporioides are discussed.

• The Plant Pathology Journal
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• v.25 no.2
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• pp.128-135
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• 2009

The survival of Colletotrichum acutatum was investigated in soil, infected fruits, and infected fruit debris incorporated into soil at several temperatures with different soil moisture levels. Samples were examined at 2-week intervals for 18 weeks to determine the survival of the pathogen based on the number of colony forming unit (CFU) of C. acutatum recovered on a semi-selective medium. C. acutatum conidia survived in both sterile and non-sterile soil at 4 and $10^{\circ}C$ for 18 weeks. If infected pepper fruits were completely dried, C. acutatum survived for 18 weeks at temperature from 4 to $20^{\circ}C$. Soil temperature and moisture affected the survival of C. acutatum in infected fruit debris incorporated into soil after air-drying. The effect of soil moisture on survival was weaker at low temperatures than at high temperatures. For up to 16 weeks, conidia were recovered from fruit debris in soil that had been kept at 4 to $20^{\circ}C$ and below 6% soil moisture. Conidia were recovered from fields until approximately 6 months after pepper fruits were harvested. Using PCR with species-specific primers and a pathogenicity test, we identified conidia recovered from soil and infected fruit from both the laboratory and field as C. acutatum and as the primary inoculum causing pepper anthracnose.

• Research in Plant Disease
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• v.18 no.1
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• pp.62-64
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• 2012

Anthracnose was occurred on black raspberry (Rubus coreanus) grown at Gochang areas of Korea during the period of 2003-2009. Black raspberry was afflicted by anthracnose with initial lesion of dark brown circular spots on the naturally infected stems and petioles. The irregular spots was either fused or progressed into circular or elliptical shape. The causal fungi of anthracnose were isolated from the diseased plants and identified as Colltotrichum gloeosporioides, C. coccodes and C. acutatum based on the morphological and cultural characteristics. All isolates of C. gloeosporioides, C. coccodes and C. acutatum produced similar symptoms under pathogenic examination through artificial inoculation.