• 식물병연구
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• 제28권2호
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• pp.57-60
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• 2022

Leaves of Chionanthus retusus were found to be damaged by leaf spot disease associated with a fungus in Iksan, Korea. Leaf spots were angular to irregular, vein-limited, scattered, 1-8 mm diameter, brownish-gray to dark brown when dry, with heavy fructification. The pathogen causes premature defoliation of C. retusus plant and was identified as Pseudocercospora chionanthi-retusi based on morphological and molecular-phylogenetic analyses. The phylogenetic tree was constructed using multi-locus DNA sequence data of partial actin (actA), partial translation elongation factor 1-alfa (tef1), partial DNA-directed RNA polymerase II second largest subunit (rpb2) genes, and internal transcribed spacer regions. Current study provides detail morphological description of P. chionanthi-retusi on C. retusus in Korea, with supports of phylogenetic analysis and pathogenicity test.

• The Plant Pathology Journal
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• 제37권4호
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• pp.339-346
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• 2021

Prevalence of tan spot of wheat caused by the fungus Pyrenophora tritici-repentis has become more prevalent in Oklahoma as no-till cultivation in wheat has increased. Hence, developing wheat varieties resistant to tan spot has been emphasized, and selecting pathogen isolates to screen for resistance to this disease is critical. Twelve isolates of P. tritici-repentis were used to inoculate 11 wheat cultivars in a greenhouse study in splitplot experiments. Virulence of isolates and cultivar resistance were measured in percent leaf area infection for all possible isolate x cultivar interactions. Isolates differed significantly (P < 0.01) in virulence on wheat cultivars, and cultivars differed significantly in disease reaction to isolates. Increased virulence of isolates detected increased variability in cultivar response (percent leaf area infection) (r = 0.56, P < 0.05) while increased susceptibility in cultivars detected increased variance in virulence of the isolates (r = 0.76, P < 0.01). A significant isolate × cultivar interaction indicated specificity between isolates and cultivars, however, cluster analysis indicated low to moderate physiological specialization. Similarity in wheat cultivars in response to pathogen isolates also was determined by cluster analysis. The use of diverse isolates of the fungus would facilitate evaluation of resistance in wheat cultivars to tan spot.

• Current Research on Agriculture and Life Sciences
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• 제23권
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• pp.43-51
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• 2005

멕시코와 네팔에서 수집한 고추 유전자원 50점과 이병성 및 저항성 대조품종에 Stemphylium solani와 S. lycopersici 의 혼합접종으로 흰별무늬병(gray leaf spot)에 대한 저항성을 검정하고, 살균제를 살포하여 회복시킨 다음 다시 Xanthomonas campestris pv. vesicatoria를 접종하여 더뎅이병에 대한 저항성을 검정하였다 더뎅이병에는 KC866, KC872, KC902, KC905이 이미 알려진 KC43, KC47, KC220, KC319, KC320, KC380 등과 함께 저항성으로 나타났다. 더뎅이병, bacterial spot)에는 KC897이 이미 저항성으로 보고된 KC177(PI163192)보다 발병이 적어 가장 우수한 것으로 나타났으며 이어서 네팔에서 도입된 KC889, KC896, KC898이 저항성으로 나타났다.

• 한국식물병리학회지
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• 제12권3호
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• pp.363-367
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• 1996

배나무잎 이상반점증상의 이병여부를 조기에 판별할 수 있는 가장 간편한 검정방법을 개발코자 시험하였다. 접목시기는 늦어질수록 병징발현율이 감소하였다. 접목방법은 2중절접, 2중삭아절접 순으로 양호하였으나 숙련된 기술이 필요한 이중절접방법보다 간편한 2중삭아절접 방법이 대량검정에 적합하였다. 이상반점증상의 전염에 필요한 최소 접촉시간은 1일 이상이었고 칼루스가 형성되어 접목부위가 활착된 21일 이후에서 발병이 가장 높았다.

• The Plant Pathology Journal
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• 제15권2호
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• pp.124-126
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• 1999

A fungus associated with the leaf spot of German iris (Iris germanica) was identified as Cladosporium iridis based on the morphological characteristics of the condiophores and conidia. A conidial suspension of the fungus was artificially inoculated onto a healthy unwounded plant, proving its pathogenicity. This is the first record of this disease from Korea.

• The Plant Pathology Journal
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• 제20권2호
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• pp.85-91
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• 2004

A disease causing severe leaf spots in pepper plants has been observed in northern Gyeongbuk and Gangwon provinces in Korea since 1994. The current study diagnosed the disease as gray leaf spot caused by Stemphylium solani Weber and S. lycopersici (Enjoji) Yamamoto, both of which are pathogenic in pepper and tomato plants. Although the disease has been found in almost all areas where peppers are grown, it is more severe in mountain terrains where the nights are cool. Both species of pathogenic fungi were found to sporu-late profusely on V-8 juice agar in plastic or Pyrex glass Petri dishes, although not in domestically-produced glass Petri dishes, when cultured at $20^{\circ}C$ under irradi-ation from a daylight fluorescent lamp with a 12-hour light and dark alternation. The domestically-produced glass Petri dishes, which are made of window glass, were found to block near ultraviolet wavelengths, around and below 300 nm, which explained why the fungi did not sporulate. However, sporulation decreased at above $25^{\circ}C$ and most isolates failed to sporulate above $27^{\circ}C$. The worst level of disease was obtained when the inoculated plants were incubated with a $15^{\circ}C$ night and $20^{\circ}C$ day temperature regime relative to 4 night/day temperature combinations (15/20, 20/25, 25/30, and 30/35$^{\circ}C$).

• 식물병연구
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• 제16권1호
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• pp.97-100
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• 2010

2009년 진주시 수곡면 딸기 노지재배 육묘 포장과 하동군 옥종면 촉성재배 시설하우스 딸기포장에서 병이 발생하였다. 병징은 잎에 수침상의 작은 반점이 서서히 생기면서 엽맥의 주위에 다각형의 모무늬 병반이 나타나고 노란색의 달무리가 형성하는 것이 특징이다. 병든 잎은 서서히 시들고 암갈색으로 말라 죽는다. YDC 배지 상에서 병원균의 균총은 노란색을 띤 오랜지 색소를 분비하며 둥근 콜로니를 형성하고 단극모를 가지고 있다. 딸기에 접종한 결과 병원성이 잘 나타났다. 이상과 같이 딸기에 발생한 병정, 병원균의 특징 및 병원성을 검정한 결과 Xanthomonas fragariae에 의한 딸기 세균성모무늬병으로 동정하였다.

• 한국작물학회지
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• 제51권3호
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• pp.199-203
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• 2006

벼 깨씨무늬병 발병 원인을 구명하기 위하여 경북지역 상습발생지 토양을 대상으로 토양특성, 식물체의 양분함량 및 이병정도에 따른 벼 수량감소 정도를 조사하고 깨씨무늬병 발생에 영향을 주는 인자를 분석한 결과는 다음과 같다. 1. 발병포장의 토양유형은 양분보유력이 낮은 사질습답 50%, 사질답이 28.3%로 전체 78.3%였고, 배수불량 토양이 67.4%를 차지하였다. 2. 병 발생이 심한 영남내륙산간 및 동해안 중, 남부지역에서 강수량이 많았고, 평균기온, 최고기온, 최저기온 및 습도와 깨씨무늬병 발병과는 관계는 부의 상관이 있었고, 강수량과는 정의 상관이 없었다. 3. 발병포장의 토양 화학성은 경북지역 논토양의 화학성에 비해 유기물, 치환성양이온, 유효규산 함량이 매우 낮은 편이며, 특히 정상지에 비해 유효규산, 아연함량이 유의하게 낮았다. 4. 이병주의 양분함량은 정상주에 비해 질소, 규산의 함량이 매우 낮았다. 5. 피해가 심한 벼는 정상 벼에 비해 간장 및 수장이 짧았고, 등숙비율은 27.9% 감소되었으며, 쌀 수량은 약 37% 정도 감수되었다. 6. 벼 깨씨무늬병 발병에 따른 미질 특성은 피해가 심할 수록 쇄미 및 심복백미의 증가로 완전미율이 11.5% 정도 더 떨어졌으며, 단백질 함량은 현저히 높아져 식미치는 피해가 높을수록 현저히 저하되었다. 7. 따라서 깨씨무늬병 발생은 양분보유력이 낮고 양분의 용탈이 심하며 유효규산 함량이 낮은 사질토양에서 주로 발생되며 생육후기 양분결핍에 의해 주로 발생되는 것으로 사료되었다.

• The Plant Pathology Journal
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• 제27권4호
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• pp.360-366
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• 2011

Bacterial leaf spot of Euphorbia pulcherrima has been reported in many countries. Characterization by polyphasic approaches indicated that the isolates from India, USA and New Zealand could be distinguished based on rep-PCR profiles and gyrB phylogenies, while the Chinese isolates should be ascribed to Xanthomonas axonopodis pv. poinsettiicola.

• Mycobiology
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• 제44권2호
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• pp.93-98
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• 2016

A new leaf spot disease was observed on leaves of Rheum palmatum (Chinese rhubarb) in Northwest China (Gansu Province) starting in 2005. A Septoria-like fungus was isolated and completion of Koch's postulates confirmed that the fungus was the casual agent of the leaf spot disease. Morphology and molecular methods were combined to identify the pathogen. The fungus produced conidiomata pycnidia and the conidia were 2~5 septate, $61.2{\sim}134.1{\mu}m$ in length and $3.53{\sim}5.3{\mu}m$ in width, which is much larger than the known Spetoria species that infects Polygonaceae species. Phylogenic analysis of the internal transcribed spacer region confirmed that this Septoria-like fungus is within the Septoria genus but distinct from known Septoria species. Together, these morphological and phylogenetic data support that the R. palmatum infecting Septoria strain is a newly-described plant pathogenic species.