• Mycobiology
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• 제46권2호
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• pp.154-158
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• 2018

Bitter rot caused by the fungal genus Colletotrichum is a well-known, common disease of apple and causes significant yield loss. In 2013, six fungal strains were isolated from Fuji apple fruits exhibiting symptoms of bitter rot from Andong, Korea. These strains were identified as Colletotrichum fructicola and C. siamense based on morphological characteristics and multilocus sequence analysis of the internal transcribed spacer rDNA, actin, calmodulin, chitin synthase, and glyceraldehyde-3-phosphate dehydrogenase Pathogenicity tests confirmed the involvement of C. fructicola and C. siamense in the development of disease symptoms on apple fruits. This is the first report of C. fructicola and C. siamense causing bitter rot on apple fruit in Korea.

• The Plant Pathology Journal
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• 제34권6호
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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 Plant Pathology Journal
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• 제24권4호
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• pp.439-446
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• 2008

A fungicidal spray program for effective control of three major apple diseases in Korea (white rot, bitter rot, and Marssonina blotch) was developed. This was based on our previous studies showing that application of ergosterol biosynthesis inhibitors (EBIs) in early or mid-August can eradicate white rot infection in fruit and that some protective fungicides show after-infection activity against white rot. The basic spray program focused on control of white rot, the main target disease, and the fungicides were sprayed at 15-day intervals from petal fall to late August using fungicides that show after-infection and EBI activity. The basic spray program was modified over 4 successive years to improve control efficacy against bitter rot and Marssonina blotch, which sometimes cause as much damage as white rot. Modifications to the regime were made every year by replacing one fungicide in the basic program at a specific spraying time. Substitution of only one fungicide in the spray program, even early in the growing season, greatly influenced the final disease incidence at harvest. Applying this principle, a moderately efficient spray program for cv. Fuji that increased the spray interval from 10 to 15 days and thus reduced the number of sprays required per crop season was developed.

• 식물병연구
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• 제29권4호
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• pp.452-458
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• 2023

In the Goesan region, located in Chungcheongbuk-do, Korea, a significant outbreak of soft rot infections was documented in August 2021, affecting fruits of Momordica charantia, commonly known as bitter melon or bitter gourd. The symptoms included a noticeable transition to yellowing in the affected fruits, eventually leading to their collapse. The bacterial strain KNUB-09-21 was isolated from the diseased fruits. Molecular analysis, using the sequences of the 16S rRNA region and three housekeeping genes (dnaX, recA, and leuS), along with the results of compound utilization in the API ID 32 GN system, provide strong evidence for the identification of the isolate KNUB-09-21 as Pectobacterium brasiliense. The pathogenicity of strain KNUB-09-21 on M. charantia was confirmed through a controlled inoculation test. Within two days, inoculated fruits displayed soft rot symptoms closely resembling those observed in naturally affected fruits. This is the first report of soft rot on M. charantia in Korea.

• 생물환경조절학회지
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• 제17권2호
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• pp.143-149
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• 2008

포도에서 봉지 종류, 봉지 처리시기 및 식물성 오일처리에 따른 열과와 병 발생 및 과실 품질에 미치는 영향을 조사하였다. 봉지 종류별 열과 및 탄저병 경감효과는 '캠벨얼리'에서 열과 발생은 큰 차이를 인정할 수 없으나, 탄저병 발생은 무대처리를 제외한 모든 처리에서 감소하였다. '조생 캠벨얼리'에서 열과 및 탄저병 발생은 무대처리를 제외한 관행봉지, 창문봉지, 칼슘함유봉지 처리에서 감소하였다 '캠벨얼리'에서 모두 7월 5일 이전의 봉지처리에서, '거봉'에서는 각각 6월 29일과 7월 6일이전의 봉지처리 모두에서 현저하게 줄었다. 식물성오일 처리는 '조생 캠벨얼리'에서 열과 및 탄저병 발생률을 현저히 줄 일수 있었고 '캠벨얼리'에서는 과피의 칼슘함량을 증가시켰다. 봉지종류별 과실품질 중 가용성고형물은 창문봉지 처리에서 많이 감소되었으며 칼슘함유봉지 처리에서는 Hunter b값이 떨어졌다. 따라서 칼슘함유봉지 및 식물성오일 처리는 열과 경감효과가 있는 것으로 판단되었다.

• 식물병연구
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• 제27권2호
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• pp.70-75
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• 2021

The abnormal brown sunken lesions were observed on cv. RubyS apple fruits in an orchard located in Gunwi, Gyeongbuk province, Korea. The primary observed symptoms such as small round sunken lesions and small black dots on the symptomatic area were different from the reported apple diseases. The affected apple fruits were sampled and subjected to isolation of the causal agent. Cultural and morphological characteristics of isolated fungal strain, designated KNUF-20GWA4, were similar to that of Colletotrichum spp. Based on multilocus sequence analyses using internal transcribed spacer regions and partial sequences of β-tubulin, glyceraldehyde-3-phosphate dehydrogenase, chitin synthase, and actin genes, strain KNUF-20GWA4 showed 99.2-100% similarities with C. aenigma ICMP 18608 and the isolate clustered together with several other strains of this species in the phylogenetic tree. To our knowledge, this is the first report of bitter rot on apple fruits caused by C. aenigma.

• The Plant Pathology Journal
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• 제25권3호
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• pp.270-279
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• 2009

During the course of a study to develop a spraying program at 15-day spray intervals, two important findings were identified allowing for further reduction of spray frequency by increasing the spray interval. In evaluating the contribution of fungicides from a 15-day spray interval program, control of white rot, which is of prime importance in Korea, was not affected, in spite of the extended spray interval caused by omitting the fungicides during the season. In another experiment assessing the duration of the protective activities of several key fungicides used in the 15-day spray interval program, infection control was maintained for almost 30 days for some fungicide. Based on these two findings, a basic spraying program with a 25-day spray interval was developed. This program was modified for four successive years to improve the control efficacy against bitter rot and Marssonina blotch, which sometimes causes as much damage as white rot.

• 한국균학회지
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• 제26권4호통권87호
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• pp.458-465
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• 1998

사과탄저병균, Glomerella cingulata에 선택적으로 항균활성이 있는 세균을 분리한 후 형태 및 생리화학적인 특성을 기준으로 동정하여 Pseudomonas sp. DGUM 5051로 명명하였다. 분리균의 생장을 위한 최적 pH와 온도는 각각 6.0과 $30^{\circ}C$이었고, 최적 항균활성을 나타내는 pH와 온도는 각각 7.0와 $24^{\circ}C$이었다. 사용한 복합배지 중 생장 및 항균활성에 있어서는 Brucella, Brain heart infusion과 LB배지가 우수하였다. Mineral salts 배지에 유일 탄소원, 질소원 및 인산원으로 각각 Sucrose, $KNO_3$ 및 $K_2HPO_4$를 첨가하였을 때 우수한 항균활성을 나타내었다. Pseudomonas sp. DGUM 5061의 항균활성은 배양 12시간 경과 후에 나타났다.

• The Plant Pathology Journal
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• 제23권2호
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• pp.37-44
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• 2007

Colletotrichum contains many important pathogens which cause economically significant diseases of crops like pepper, strawberry, tomato and apple. Forty four isolates were collected to characterize the diversity of Colletotrichum causing apple anthracnose in various regions of Korea. They were analyzed by random amplified polymorphic DNA (RAPD), internal transcribed spacer (ITS) of rDNA and partial $\beta$-tubulin gene DNA sequence, and culture characteristics on PDA and PDA-Benomyl. From the results of molecular analyses, 31 strains belonged to Colletotrichum gloeosporioides, ribosomal DNA group (RG) 4 of Moriwaki et al. (2002), 8 strains belonged to C. acutatum, A2 group of Talhinhas et al. (2005) and 5 strains to C. acutatum, A3 group of Talhinhas et al. (2005). Most isolates of C. gloeosporioides RG4 grew faster on PDA than strains of C. acutatum, A2 and A3 groups and most RG4 strains were sensitive to Benomyl. However, a few strains of RG4 grew slower and were resistant to Benomyl. On the basis of molecular characteristics, apple isolates of C. acutatum were clearly differentiated from red pepper isolates of the species, but apple isolates of C. gloeosporioides were not.

• 한국응용곤충학회지
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• 제10권1호
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• pp.39-41
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• 1971

사과 탄저병은 매년 특정기간의 과실에 한하여 발병한다는 것으로 미루어 보아 지간에서 자낭각의 형으로 월동하는 것으로 보고 연구한 결과는 다음과 같다. 1) 사과, 포도, 아까시아 등의 공시나무가지에 병균이 감염되어서 포자퇴가 형성되는 것으로 보아 본 병균은 나무가지에서 월동이 가능한 것으로 생각된다. 우리나라에서는 발견하지 못했던 자낭세대가 접종된 공시나무가지의 병환부의 껍질속과 병과의 표피밑에서 검출되었으므로 자낭각의 형으로 지간에서 월동하여 일차전염원이 될 수 있다는 사실을 알았다.