• 식물병연구
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• 제9권3호
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• pp.116-120
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• 2003

참다래 잎으로부터 궤양병균인 Pseudomnoas syringae pv. actinidiae를 배양하여 PCR을 통해 검출하는 방법을 개발하였다. Nested PCR을 위해 두 set의 primer를 식물 독소인 coronatine의 생합성에 관여하는 유전자 cfl의 염기서열로부터 설계하였다. 이 primer set를 사용하여 665rhk 310-bp의 절편이 증폭되었으며 nested PCR을 통한 궤양병균의 검출한계는 20 CFU/ml이었다. 4 그루의 참다래 나무로부터 노란색 무리로 나타나는 궤양병 초기 증상을 보이는 잎을 채취하여 pepton-sucrose 액체배지에 넣어 $16^{\circ}$C에서 12시간 배양 한뒤 PCR 을 시행한 결과 한 시료에서 예상했던 밴드가 증폭되었고 이듬해 봄 이 나무가 궤양병에 감염되었음을 확인하였다.

• 식물병연구
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• 제17권3호
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• pp.364-368
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• 2011

Gray mold caused by Botrytis cinerea was found on a carrot seedling in a greenhouse and a field at Daegwallryeong, Gangwon Province in 2007-2009. Symptoms included irregular, brown, blight, or chlorotic halo on leaves and petioles of the carrots. Fungal conidia were globose to subglobose or ellipsoid, hyaline or pale brown, nonseptate, one celled, $7.2-18.2{\times}4.5-11\;{\mu}m$ ($12.1{\times}8.3\;{\mu}m$) in size, and were formed on botryose heads. B. cinerea colonies were hyaline on PDA, and then turned gray and later changed dark gray or brown when spores appeared. The fungal growth stopped at $35^{\circ}C$, temperature range for proper growth was $15-25^{\circ}C$ on MEA and PDA. Carrots inoculated with $1{\times}10^5$ ml conidial suspension were incubated in a moist chamber at $25{\pm}1^{\circ}C$ for pathogenicity testing. Symptoms included irregular, brown, water-soaked rot on carrot roots and irregular, pale brown or dark brown, water-soaked rot on leaves. Symptoms were similar to the original symptoms under natural conditions. The pathogen was reisolated from diseased leaves, sliced roots, and whole roots after inoculation. As a result, this is the first report of carrot gray mold caused by B. cinerea in Korea.

• Journal of Microbiology and Biotechnology
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• 제16권3호
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• pp.423-430
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• 2006

A total of 367 isolates of Phytophthora infestans was collected from the leaf samples of late blight disease from five provinces in Korea over the three growing seasons of 2002-2004. Of the 367 isolates, 337 isolates were of the A1 mating type, and 30 isolates were of A2 mating type, showing that the majority was A1 mating type. Profiles of Gpi and Pep defined four allozyme genotypes among the total of 367 isolates. All four allozyme genotypes could be distinguished on the basis of Gpi profiles alone, whereas all isolates were homozygous at the Pep locus (100/100). The mitochondrial DNA haplotype of all isolates were the IIa haplotype. Amplification of the genomic DNAs extracted from eight isolates of each mating type by polymerase chain reaction with the selected primer (OPC-5 primer) produced a total of 20 DNA bands, of which 11 bands were polymorphic. According to the RAPD analysis using the OPC-5 primer, 106 isolates including two standard isolates were separated into 8 groups at the similarity level of 92.5%. The RAPD groups were not correlated with the allozyme genotypes and the isolated locations. All of the eight RAPD groups were identified in Gangwon-do, suggesting that Gangwon-do is the center of origin of the P. infestans in Korea. A 600-bp DNA band generated with the OPC-5 primer was specific to A1 mating type isolates, but not detected with A2 mating type, showing that the specific PCR primer can distinguish different mating types in P. infestans.

• 한국응용곤충학회지
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• 제19권1호
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• pp.39-44
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• 1980

배나무 붉은별무늬병은 1973년이래 해마다 발병이 증가하여 1975연에는 발병엽율 $60.3\%$에 달하였으며 1974년 향나무 재식규제조치이후 감소하였다. 붉은별무늬병원균의 동포자발아 시기는 4월중순부터 5월중순까지 였으며 인공강우에 의하여 그 발아시기를 5일 전에 알 수 있었다. 성숙한 동포자퇴의 포자발아에는 3시간 이상의 계속되는 비로서 상당량의 강수가 필요하였다. 배나무의 감염은 강우중이나 강우직후에 이루워지고 있었으며 강양 24시간 이후의 감염은 없었다. 감염후 배나무에서의 잠복기간은 $9\~10$일이었다. 배나무와 향나무사이의 지리가 100m 이내인 경우에는 거의 모든 배나무가 발병하였으나 거리가 멀어짐에 따라 발병율도 감소하였으며 2km 이상에서는 발병이 없었다.

• 식물병연구
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• 제23권1호
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• pp.82-87
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• 2017

During 2012 to 2014, a survey for the presence of viral diseases in yam plants was carried out in a field of the Institute for Bioresources Research in Gyeongsangbuk-do, Korea. A total of 88 leaf samples were collected and tested by reverse transcription polymerase chain reaction using specific primer sets. Eighty-one samples were positive for Broad bean wilt virus 2 (BBWV2), Chinese yam necrotic mosaic virus (ChYNMV), Cucumber mosaic virus (CMV), Japanese yam mosaic virus (JYMV), and Yam mild mosaic virus (YMMV), whereas Yam mosaic virus (YMV) was not detected. Additionally, seven samples were negative for all viruses. Several samples exhibited mixed (double and triple) infections. Three viruses (CMV, JYMV, and YMMV) were detected for the first time in yam plants in Korea. A BLAST search showed that three viruses shared nucleotide identities with CMV-Ca (98%), JYMV-O2 (91%), and YMMV-TG_NH_1 (86%). Thus, our findings confirmed that yam plants cultivated in Korea were infected with multiple viruses with three of these viruses reported for the first time in Korea.

• 식물병연구
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• 제11권2호
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• pp.106-114
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• 2005

To breed powdery mildew resistant varieties, 104 accessions of Cucurbita spp. germplasm were evaluated. Powdery mildew resistance and horticultural characteristics of the accessions were investigated in the field conditions. C. martinezii was selected for high resistance to powdery mildew in the field. The growth of powdery mildew pathogen and response of leaf surface tissue to the pathogen were observed after artificial inoculation to resistant C martinezii and susceptible C. moschata cv. 'Wonye No.402'. Mycelium growth was very clearly different between resistant C. martinezii and susceptible C moschata cv. 'Wonye No. 402' at 5 days after inoculation at the adult stage. Interspecific hybridization was attempted to transfer powdery mildew resistance gene(s) from C. martinezii to C. moschata. A single dominant gene action was postulated as deter mining powdery mildew resistance at the seedling stage. But for the effective selection of powdery mildew resistant individuals, it was established that adult plant resistance should be confirmed in the field conditions after the seedling test. Through the seedling and field tests, C. moschata lines resistant to powdery mildew and superior to horticultural characteristics, were selected after 2 backcrossing and 3 selfing generations. The fruit characteristics of newly developed lines were similar to those of the recurrent parent, 'Jaechenjarae'.

• The Plant Pathology Journal
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• 제33권4호
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• pp.382-392
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• 2017

This study reports the findings of a distinct Potato virus Y (PVY) isolate found in Northeast China. One hundred and ten samples (leaves and tubers) were collected from potato plants showing mosaic symptoms around the city of Harbin in Heilongjiang province of China. The collected tubers were planted and let to grow in a greenhouse. New potato plants generated from these tubers showed similar symptoms, except for one plant. Subsequent serological analyses revealed PVY as the causing agent of the disease. A novel PVY isolate (referred to as HLJ-C-44 in this study) was isolated from this sample showing unique mild mosaic and crisped leaf margin symptoms. The complete genome of this isolate was analyzed and determined. The results showed that HLJ-C-44 is a typical PVY isolate. Phylogenetic analysis indicated that this isolate belongs to the N-Wi strain group of PVY recombinants ($PVY^{N-Wi}$) and also shared the highest overall sequence identity (nucleotide and amino acid) with other members of this strain group. However, recombination analysis of isolate HLJ-C-44 revealed a recombination pattern that differed from that of other $PVY^{N-Wi}$ isolates. Moreover, biological assays in four different potato cultivars and in Nicotiana tabacum also revealed a different phenotypic response than that of a typical $PVY^{N-Wi}$ isolate. This data, combined, suggest that HLJ-C-44 is a novel PVY recombinant with distinct biological properties.

• 식물병연구
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• 제25권1호
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• pp.43-47
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• 2019

Apple chlorotic leaf spot virus (ACLSV), Apple stem pitting virus (ASPV), Apple stem grooving virus (ASGV), and Apple scar skin viroid (ASSVd) are economically important viruses that infect pear tree species worldwide. To evaluate the prevalence of these viruses in Korea, we investigated infection degree of three viruses and one viroid for the commercial nursery trees of the pear cultivars, Niitaka, Chuwhang, Wonwhang, and Whasan in 2017 and 2018. The results showed that the infection ratio of ACLSV, ASPV, ASGV, and ASSVd for the scion of pear cultivar Niitaka was 10%, 45%, 77%, and 50%, respectively. From the scion of pear cultivar Chuwhang, infection ratios of ASPV, ASGV, and ASSVd were found to be 70%, 50%, and 60%, respectively. From the scion of pear cultivar Whasan, infection ratios of ACLSV, ASPV, ASGV and ASSVd were found to be 40%, 60%, 93%, and 20%, respectively. From the root stock of pear cultivar Wonwhang, infection ratios of ACLSV, ASPV, ASGV, and ASSVd showed 28%, 57%, 100%, and 14%, respectively. ASGV had the highest recorded infection rate, and ACLSV was characterized by the lowest infection rate. The mixed infection ratio of Niitaka, Chuwhang, Whasan, and Wonwhang was 45%, 60%, 70%, and 85%, respectively.

• 식물병연구
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• 제30권2호
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• pp.157-164
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• 2024

Jack bean (Canavalia ensiformis) is one of healthy products for fermented or functional food in Korea and is widely distributed and cultivated worldwide. During August 2022, Jack bean plants showing symptoms of yellow flecks, chlorosis, necrotic spots and mosaic were observed in Jangheung-gun, South Korea. By transmission electron microscopy, flexuous filamentous virus particles of approximately 750×13 nm in size were observed in the symptomatic leaf samples. The infection of a Korean isolate of clover yellow vein virus (ClYVV-Ce-JH) was confirmed using double antibody sandwich enzyme-linked sorbent assay, reverse transcription polymerase chain reaction and high-throughput sequencing. The complete genome sequence of ClYVV-Ce-JH consists of 9,549 nucleotides (nt) excluding the poly (A) tail and encodes 3,072 amino acids (aa), with an AUG start and UAG stop codon, containing one open reading frame that is typical of a potyvirus polyprotein. The polyprotein of ClYVV-Ce-JH was divided into ten proteins and each protein's cleavage sites were determined. The coat protein (CP) and polyprotein of ClYVV-Ce-JH were compared at the nt and aa levels with those of the previously reported 14 ClYVV isolates. ClYVV-Ce-JH shared 92.62% to 99.63% and 93.39% to 98.05% at the CP and polyprotein homology. To our knowledge, this is the first report of a Korean isolate of ClYVV from Jack bean plants and the complete genome sequence of a ClYVV Jack bean isolate in the world.

• 농약과학회지
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• 제4권3호
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• pp.40-46
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• 2000

Phoma sp.에 의한 대추나무 점무늬병 방제용 살균제를 선발하기 위하여 모두 26종의 살균제를 대상으로 $250{\mu}g\;a.i./m{\ell}$ 의 농도에서 균사생장을 조사한 결과 benomyl 등 8종의 살균제가 균사생장 억제효과를 보였다. 이들 8종의 살균제에 대하여 균사 최소생장억제농도 (MIC)와 포자발아억제력을 조사하였는데, myclobutanil 등 3종은 포자발아억제력은 우수하였으나 포장에서 사용시의 권장농도보다도 높은 MIC 값을 보여 이들을 제외한 5종 (benomyl, iminoctadine-triacetate (IT), iprodione과 propineb 합제 (IP), thiophanate-methyl과 triflumizole 합제 (TT), carbendazim과 kasugamycin 합제 (CK)에 대하여 온실에서 예방효과와 치료효과를 검정하였다. Benomyl, CK, TT 등의 MIC는 $10-50{\mu}g\;a.i./m{\ell}$ 사이에 있음이 확인되었으며, IP와 IT의 MIC는 $50-250{\mu}g\;a.i./m{\ell}$이었다. 또한 포자발아 억제시험 결과 IT는 $0.4{\mu}ga\;.i./m{\ell}$의 농도에서 99%, 그리고 CK와 TT는 $10{\mu}g\;a.i./m{\ell}$에서 90% 이상의 포자발아를 억제하였으나, benomyl과 IP는 $10{\mu}g\;a.i./m{\ell}$에서 각각 22.8%와 9.2%라는 낮은 억제율을 보였다. 예방효과시험에서 CK와 TT는 모두 권장 농도 (1,000 ppm)에서 70% 내외, 배량 농도 (2,000 ppm)에서 90% 내외의 방제 효과를 보였고, benomyl은 2,000 ppm, IP는 4,000 ppm, IT는 8,000 ppm에서 70% 내외의 병 방제 효과를 보였다. 치료효과시험에서는 각 살균제를 1,000 ppm으로 처리하였을 때 benomyl이 90% 이상의 방제가를, 그리고 CK와 TT가 70-80%의 방제가를 보였다. 반면에 IP는 2,000 ppm에서도 방제가가 6.7%로 매우 낮았으며, IT는 전혀 방제효과가 없었다. 더구나 IT 는 예방 효과 시험과 치료 효과 시험 모두에서 약해를 보였다. 따라서 대추나무 점무의병의 방제약제로는 benomyl이 가장 적합한 것으로 밝혀졌으며, 저항성 균의 출현 등을 저지하기 위해서 병이 발생하기 전에는 CK나 TT를 사용하고, 병이 발생한 이후에는 benomyl을 사용하는 것이 바람직할 것으로 생각한다.