• 농업과학연구
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• 제50권4호
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• pp.723-734
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• 2023

Erwinia pyrifoliae, which causes black shoot blight in apple and pear trees, was first identified in Korea in 1995. Extensive measures are typically used to control the disease by eradicating trees in diagnosed orchards, owing to the detrimental impact of the disease on apple and pear production. However, despite governmental efforts, the disease has continuously spread. In this study, we analyzed the current status of the black shoot blight occurrence in apple and pear orchards between 1995 to 2022. Our findings reveal that over the past 28 years, black shoot blight has occurred in 26 cities and districts across five Korean provinces. The affected regions are predominantly concentrated in the northern part of Korea, including the Gangwon and Gyeonggi provinces. Furthermore, black shoot blight has gradually expanded to the northern provincial regions of Chungbuk, Chungnam, and Gyeongbuk, which are centrally situated in Korea. Furthermore, the occurrence pattern of black shoot blight differed between apple and pear orchards; in apple orchards, black shoot blight occurred consistently each year, with a sudden increase in cases in 2020; however, in pear orchards, it has considerably decreased since 2007. To the best of our knowledge, this is the first comprehensive report on the occurrence of black shoot blight in apple and pear trees in 28 years, and the results will provide valuable insights for future disease management strategies.

• Weed & Turfgrass Science
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• 제5권2호
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• pp.51-59
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• 2016

본 연구는 2015년 2월부터 8월까지 경상북도 12개 시군에서 경북 지역의 주요 과수인 사과, 포도, 복숭아, 포도, 자두 과원에 발생되는 잡초종을 동계잡초와 하계잡초로 나누어 우점도를 조사하였다. 사과 과원에서는 36과 105종, 포도 과원 34과 126종, 복숭아 과원 34과 126종, 배 과원 33과 98종, 자두 과원 36과 111종이었다. 과원별 우점도는 사과 과원의 경우 이년생 잡초 6.09%, 포도 과원의 경우 이년생 잡초 7.32%, 복숭아 과원의 경우 일년생 잡초 4.74%, 배 과원의 경우 일년생 잡초 6.57%, 자두 과원의 경우 이년생 잡초 5.38%였다. 주요 과원별 동계잡초에 대한 과와 종수는 사과 과원 31과 89종, 포도 과원 28과 71종, 복숭아 과원 32과 111종, 배 과원 27과 68종, 자두 과원 33과 83종이었고 하계잡초에 대한 과와 종수는 사과 과원 31과 101종, 포도 과원 27과 69종, 복숭아 과원 29과 91종, 배 과원 31과 94종, 자두 과원 31과 97종이였다. 주요 과원별 동계 우점잡초는 사과 과원(냉이), 배 과원(별꽃), 복숭아 과원(냉이), 포도 과원(냉이), 자두 과원(망초)이었고, 하계우점잡초는 사과 과원(깨풀), 배 과원(쑥), 복숭아 과원(강아지풀), 포도 과원(강아지풀), 자두 과원(강아지풀)이었다.

• 한국균학회지
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• 제51권4호
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• pp.471-490
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• 2023

Soil is a rich source of saprobic and pathogenic fungi in crop cultivation areas. Compared with that of the fruit trees, scarce information is available regarding the fungi present in orchard soils in Korea. We sampled rhizosphere soils of apple and pear trees from several orchards in Cheongju, Anseong, and Cheonan, Korea. During the processing of soil fungi, seven unrecorded species of the phylum Ascomycota were isolated. These included Acrocalymma walkeri, Clonostachys krabiensis, Coniella vitis, Cosmospora diminuta, Lasiobolidium spirale, Penicillium vallebormidaense, and Pseudothielavia arxii. All the species were identified and described based on morphological characteristics and molecular analysis of the ITS1-5.8S-ITS2 region and the large subunit of nuclear ribosomal RNA gene and partial β-tubulin gene (BenA) sequences. Descriptions and illustrations of the morphological characteristics are provided.

• 식물병연구
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• 제25권2호
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• pp.89-93
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• 2019

Fire blight disease caused by the bacterium, Erwinia amylovora, was observed in apple and pear orchards in Korea in 2015. Since then, it has spread, sometimes over long distances to other orchards. Therefore, we examined the ability of E. amylovora to survive in soils and on the surfaces of common materials such as T-shirts, wrist bands, pruning shears, and rubber boots by both conventional PCR (cPCR) and quantitative PCR (qPCR) methods. E. amylovora was detected in all materials tested in this study and survived for sufficiently long periods to cause fire blight disease in new sites. Thus, based on the results of this study, sanitation protocols must be applied to equipment during orchard work.

• 식물병연구
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• 제27권3호
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• pp.91-98
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• 2021

The current social demand for organic, sustainable, and eco-friendly approaches for farming, while ensuring the health and productivity of crops is increasing rapidly. Biocontrol agents are applied to crops to ensure biological control of plant pathogens. Research on the biological control of white root rot disease caused by a soil-borne pathogen, Rosellinia necatrix, is limited in pears compared to that in apple and avocado. This pathogenic fungus has an extensive host range, and symptoms of this disease include rotting of roots, yellowing and falling of leaves, wilting, and finally tree death. The severity of the disease caused by R. necatrix, makes it the most harmful fungal pathogen infecting the economical fruit tree species, such as pears, and is one of the main limiting factors in pear farming, with devastating effects on plant health and yield. In addition to agronomic and cultural practices, growers use chemical treatments to control the disease. However, rising public concern about environmental pollution and harmful effects of chemicals in humans and animals has facilitated the search for novel and environmentally friendly disease control methods. This review will briefly summarize the current status of biocontrol agents, ecofriendly methods, and possible approaches to control disease in pear orchards.

• 식물병연구
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• 제29권2호
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• pp.193-199
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• 2023

The apple stem grooving virus (ASGV) is one of the most harmful latent viruses infecting pear orchards worldwide. To examine the genetic diversity of ASGV in Korean pear orchards, the complete coat protein (CP) gene of five ASGV isolates collected from various regions were identified. The five Korean ASGV isolates showed 88-96% nucleotide identity with the 11 isolates worldwide occurring elsewhere in the world. Phylogenetic analysis of five isolates, as well as the previously sequenced isolates, indicated that the ASGV clusters had no correlation with the host or geographical regions of origin. Recombination analysis showed that one of the five Korean isolates is a recombinant, with a recombination site in the CP gene region (nt 532-708). This study is the first report of natural recombination within the CP gene of ASGV isolates from pears grown in Korea.

• The Plant Pathology Journal
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• 제37권3호
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• pp.258-267
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• 2021

Asian pear (Pyrus pyrifolia) is a widely cultivated and commercially important fruit crop, which is occasionally subject to severe economic losses due to latent viral infections. Thus, the aim of the present study was to examine and provide a comprehensive overview of virus populations infecting a major pear cultivar ('Singo') in Korea. From June 2017 to October 2019, leaf samples (n = 110) of pear trees from 35 orchards in five major pear-producing regions were collected and subjected to RNA sequencing. Most virus-associated contigs matched the sequences of known viruses, including apple stem grooving virus (ASGV) and apple stem pitting virus (ASPV). However, some contigs matched the sequences of apple green crinkle-associated virus and cucumber mosaic virus. In addition, three complete or nearly complete genomes were constructed based on transcriptome data and subjected to phylogenetic analyses. Based on the number of virus-associated reads, ASGV and ASPV were identified as the dominant viruses of 'Singo.' The present study describes the virome of a major pear cultivar in Korea, and looks into the diversity of viral communities in this cultivar. This study can provide valuable information on the complexity of genetic variability of viruses infecting pear trees.

• The Plant Pathology Journal
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• 제38권4호
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• pp.355-365
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• 2022

Erwinia amylovora and E. pyrifoliae are the causative agents of destructive diseases in both apple and pear trees viz. fire blight and black shoot blight, respectively. Since the introduction of fire blight in Korea in 2015, the occurrence of both pathogens has been independently reported. The co-incidence of these diseases is highly probable given the co-existence of their pathogenic bacteria in the same trees or orchards in a city/district. Hence, this study evaluated whether both diseases occurred in neighboring orchards and whether they occurred together in a single orchard. The competition and virulence of the two pathogens was compared using growth rates in vitro and in planta. Importantly, E amylovora showed significantly higher colony numbers than E. pyrifoliae when they were co-cultured in liquid media and co-inoculated into immature apple fruits and seedlings. In a comparison of the usage of major carbon sources, which are abundant in immature apple fruits and seedlings, E. amylovora also showed better growth rates than E. pyrifoliae. In virulence assays, including motility and a hypersensitive response (HR), E. amylovora demonstrated a larger diameter of travel from the inoculation site than E. pyrifoliae in both swarming and swimming motilities. E. amylovora elicited a HR in tobacco leaves when diluted from 1:1 to 1:16 but E. pyrifoliae does not elicit a HR when diluted at 1:16. Therefore, E. amylovora was concluded to have a greater competitive fitness than E. pyrifoliae.

• 식물병연구
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• 제26권4호
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• pp.222-228
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• 2020

과수 화상병을 일으키는 Erwinia amylovora는 국내에서 금지병원균으로 지정되어 화상병 발생 시, 중앙 정부의 진단을 근거로 기주를 매몰하는 공적 방제가 실시되고 있다. 국내 과수 화상병은 2015년 안성, 천안 및 제천의 43농가에서 발생하여 42.9 ha를 매몰한 것을 시작으로, 2019년 발생 지역이 11개 시군으로 확산되었으며, 총 348농가 260.4 ha가 매몰되었다. 배나무 화상병은 주로 경기남부와 충남에서 발생되었고, 발생 건수가 연평균 29±9.2건으로 매년 비교적 고르게 발생되었으며 20-30년생 과수에서 발병 비율이 가장 높았다. 반면, 사과나무 화상병은 주로 경기북부, 강원, 충북에서 발생되었고, 발생 건수가 연평균 41±57.6건으로 2018-2019년 발생건수가 크게 증가하였으며, 20년 이하의 과수의 발병 비율이 높았다. 국내 과수 화상병은 어린 사과나무에서 병의 확산이 빠르므로, 특히 미성숙 과수가 식재된 과원에서는 화상병이 발병하지 않도록 약제를 적기에 살포하는 등 예방을 철저히 하고, 발병 시 신속히 방제해야 한다.

• 한국응용곤충학회지
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• 제51권4호
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• pp.479-484
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• 2012

최근 사과원에서 복숭아순나방붙이(Grapholita dimorpha)의 발생이 보고되었다. 복숭아순나방붙이는 이와 유사한 복숭아순나방(G. molesta)이 발생하는 또 다른 기주에서도 동시에 발생이 가능하다고 제기되었다. 본 연구는 국내 여러 지역의 배과원에서 복숭아순나방붙이의 발생이 있음을 보고한다. 복숭아순나방붙이의 종 동정은 형태적 특징과 분자마커를 이용하여 실시되었다. 이들 두 종의 공통된 성페로몬 주성분으로 상호 교차 포획이 이뤄질 수 있다. 복숭아순나방붙이 페로몬트랩에 복숭아순나방붙이와 복숭아순나방이 포획되고, 복숭아순나방 페로몬트랩에 복숭아순나방과 복숭아순나방붙이가 포획되었다. 복숭아순나방붙이 트랩에 이뤄진 교차 포획비율은 지역적으로 다른 배과원에서 상호 뚜렷한 차이가 나타났다. 더욱이 이 두 종의 발생 피크도 조사한 모든 야외 지역에서 시기적으로 뚜렷한 차이를 보였다. 이러한 결과는 배 과수원에서 두 종의 성페로몬 트랩으로 얻은 모니터링 자료는 각각 서로 다른 종의 포획이 혼재하며, 이는 해당종의 발생빈도와 발생밀도가 확대 해석될 수 있음을 본 연구 자료는 제시하고 있다.