First Report of Dieback Caused by Lasiodiplodia theobromae in Strawberry Plants in Korea

Dieback in strawberry (Seolhyang cultivar) was first observed during the nursery season (June to September) in the Nonsan area of Korea in the years 2012 and 2013. Initial disease symptoms included dieback on runners, as well as black rot on roots, followed by wilting and eventually blackened, necrotic discoloration in the crowns of daughter plants. A fungus isolated from the diseased roots, runners, and crowns is close to Lasiodiplodia theobromae based on morphological characteristics. Analysis of a combined dataset assembled from sequences of the internal transcribed spacer and translation elongation factor 1-alpha genes grouped nine fungal isolates with the type strain of L. theobromae. The isolates showed strong pathogenicity on strawberry cultivars Kumhyang, Seolhyang, and Akihimae, fulfilling Koch's postulates. Based on these results, the pathogen responsible for dieback on strawberry plants in Korea was identified as L. theobromae.

Cladosporium cladosporioides and C. tenuissimum Cause Blossom Blight in Strawberry in Korea

Blossom blight in strawberry was first observed in a green house in Nonsan, Damyang, and Geochang areas of Korea, between early January to April of 2012. Disease symptoms started as a grey fungus formed on the stigma, which led to the blossom blight and eventually to black rot and necrosis of the entire flower. We isolated the fungi purely from the infected pistils and maintained them on potato dextrose agar (PDA) slants. To test Koch's postulates, we inoculated the fungi and found that all of the isolates caused disease symptoms in the flower of strawberry cultivars (Seolhyang, Maehyang, and Kumhyang). The isolates on PDA had a velvet-like appearance, and their color ranged between olivaceous-brown and smoky-grey to olive and almost black. The intercalary conidia of the isolates were elliptical to limoniform, with sizes ranging from 5.0~10.5 x 2.5~3.0 microm to 4.0~7.5 x 2.0~3.0 microm, respectively. The secondary ramoconidia of these isolates were 0- or 1-septate, with sizes ranging betweem 10.0~15.0 x 2.5~3.7 microm and 8.7~11.2 x 2.5~3.2 microm, respectively. A combined sequence analysis of the internal transcribed spacer regions, partial actin (ACT), and translation elongation factor 1-alpha (TEF) genes revealed that the strawberry isolates belonged to two groups of authentic strains, Cladosporium cladosporioides and C. tenuissimum. Based on these results, we identified the pathogens causing blossom blight in strawberries in Korea as being C. cladosporioides and C. tenuissimum.

Genetic Diversity and Pathogenicity of Cylindrocarpon destructans Isolates Obtained from Korean Panax ginseng

We analyzed the genetic diversity of Cylindrocarpon destructans isolates obtained from Korean ginseng (i.e., Panax ginseng) roots by performing virulence tests and nuclear ribosomal gene internal transcribed spacer (ITS) and mitochondrial small subunit (mt SSU) rDNA sequence analysis. The phylogenetic relationship analysis performed using ITS DNA sequences and isolates from other hosts helped confirm that all the Korean C. destructans isolates belonged to Nectria/Neonectria radicicola complex. The results of in vivo and ex vivo virulence tests showed that the C. destructans isolates could be divided into two groups according to their distinctive difference in virulence and the genetic diversity. The highly virulent Korean isolates in pathogenicity group II (PG II), together with foreign isolates from P. ginseng and P. quinquefolius, formed a single group. The weakly virulent isolates in pathogenicity group I, together with the foreign isolates from other host plants, formed another group and exhibited a greater genetic diversity than the isolates of PG II, as confirmed by the mt SSU rDNA sequence analysis. In addition, as the weakly virulent Korean isolates were genetically very similar to the foreign isolates from other hosts, they were likely to originate from hosts other than the ginseng plants.

Direct Detection of Cylindrocarpon destructans, Root Rot Pathogen of Ginseng by Nested PCR from Soil Samples

We have successfully applied the nested PCR to detect Cylindrocarpon destructans, a major pathogen causing root rot disease from ginseng seedlings in our former study. The PCR assay, in this study, was used to detect the pathogen from soils. The nested PCR using internal transcribed spacer (ITS) 1, 4 primer set and Dest 1, 4 primer set maintained the specificity in soils containing various microorganisms. For a soil DNA extraction method targeting chlamydospores, when several cell wall disrupting methods were tested, the combination of lyophilization and grinding with glass beads, which broke almost all the chlamydospores, was the strongest. The DNA extraction method which was completed based on the above was simple and time-saving because of exclusion of unnecessary stages, and efficient to apply in soils. As three ginseng fields whose histories were known were analyzed, the PCR assay resulted as our expectation derived from the field information. The direct PCR method will be utilized as a reliable and rapid tool for detecting and monitoring C. destructans in ginseng fields.

Chinese Cabbage Clubroot Pathogen, Plasmodiophora brassicae, Is Genetically Stable

Single spore isolates of Plasmodiophora brassicae e4 and e9 obtained from diseased Chinese cabbage were identified as race 4 and race 9, respectively, by the Williams' differential variety set. To confirm the possibility of variation in same generation and progeny of a single spore isolate of P. brassicae, random amplified polymorphic DNA (RAPD) analysis was conducted using the URP 3, 6 and OPA 7 primers. There was no difference in band type at each part of the gall of Chinese cabbage obtained by inoculation of e4 and e9 and amplification using the URP 3 and 6 primers when the same generation was analyzed. In addition, the progeny analysis, which was expanded to the third generation and conducted using the URP 3 and OPA 7 primers, revealed no differences in the band type of the e4 isolate. Based on these results, the single spore isolate of P. brassicae was genetically stable.

Occurrence of Narcissus Smoulder Caused by Botrytis narcissicola in Korea

Leaf blight and bulb rot symptoms were observed on narcissus plants grown in Yongin, Cheongwon and Namhae areas in Korea during disease survey from 1999 to 2002. A total of 15 isolates of Botrytis sp. were obtained from the infected plant parts of narcissus. All the isolates were identified as Botrytis narcissicola based on their morphological and cultural characteristics. Three isolates of B. narcissicola were tested for their pathogenicity to leaves and bulbs of narcissus by artificial inoculation. All the isolates induced leaf blight and bulb rot symptoms on the plants of narcissus by artificial inoculation. The symptoms induced by artificial inoculation were similar to those observed in the fields. This is the first report of narcissus smoulder caused by B. narcissicola in Korea.

Comparison of Characteristics of Ganoderma lucidum According to Geographical Origins (III): Classification between Species of Genus Ganoderma Using Dikaryon-Monokaryon Mating

A Monokaryotic strain G8M without clamp connections was isolated from germinated basidiospore that was obtained from cultivated fruit body. Strain G8M was used as a tester isolate for 'dikaryon-monokaryon mating' (di-mon mating) with the strains of Ganoderma lucidum, G6 and G35 (Korean wild strains), G3 (Taiwan), G4 (Canada), G15 (America), G. oregonense G24, G. resinaceum G28, G. oerstedii G23, and G. subamboinense G29. Isolate G8M was compatible to Korean strains G6 and G35, but was incompatible to foreign strains G3, G4, or G15. Compatible reactions between strains were readily observed macroscopically. Clear barrage lines formed between incompatible strains. These clear lines were not apparent in compatible di-mon matings. The Korean strains were morphologically distinct; they did not form any chlamydospores, and stopped growth at 35degrees C. The strains of G. lucidum from Korea may be considered as different species from Taiwan, Canadian and American cultures.

Comparison of Characteristics of Ganoderma lucidum According to Geographical Origins : Consideration of Morphological Characteristics(II)

Nine species of genus Ganoderma different in cultural characteristics each other were separated by histo-anatomical differences. Differences among the species and geographic distribution of G. lucidum were also analyzed to provide the criteria for the classification of Korean cultivation or wild type strains. Korean cultivation and wild type strains were quiet different from other species as well as Taiwan and North American G. lucidum strains in histo-anatomical traits of Ganoderma. Pore color of Korean G. lucidum strains was less brown than those of Taiwan and North American strains. Shapes of pores were round or circular in Korean strains but ellipsoidal or angular in Taiwan or North American strains. Pore numbers of Korean strains were more than those(4~6/mm) of Taiwan or North American strains. Hardness of the pileus of Korean strains was much more than that of Taiwan or North American strains. Such characteristics of Korean strains were different from those of other species of Ganoderma. Korean G. lucidum strains could be classified into the other group because they had many different traits in growth characteristics of fruiting bodies and histo-anatomical characteristics from those of Taiwan or North American G. lucidum and other species of G. lucidum complex.

Comparison of Characteristics of Ganoderma lucidum According to Geographical Origins : Consideration of Growth Characteristics(I)

Nine species of genus Ganoderma collected in Korea and abroad including Ganoderma lucidum complex and G. lucidum were compared by investigating growth characteristics. In the bottle culture, the mycelial growth periods of G. lucidum from Taiwan and North America was 26 to 30 days compared to that of Korean G. lucidum, which was 30 to 32 days. Cultivation period of Taiwan and North American isolates was 30 to 32 days which were 11 to 17 days shorter than those of Korean isolates. Biological efficiency of Taiwan and North American isolates were ranged from 3.3 to 5.5%, which were apparently lower than that of Korean isolates which ranged from 6.2 to 9.4%. Korean isolates had longer stipes(15~40 mm) and more number of pileus(4~6/bottle) than those of Taiwan and North American isolates. The G. lucidum isolates collected from Korea will be regarded as the independent species from the G. lucidum collected from Taiwan and North America since, the G. lucidum from Korea showed much different growth characteristics in various aspects compared to the G. lucidum from Taiwan and North America.

T-Cell Lymphoma with Rosai-Dorfman Syndrome-Like Feature / 대한혈액학회지

T-cell lymphoma is heterogeneous with respect to clinical presentation, course, and morphology, but it is rarely associated with sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman Syndrome). We report a case of T-cell lymphoma with Rosai-Dorfman Syndrome like feature in a 31-years-old woman who presented severe non-immune hemolytic anemia and massive retroperitoneal and cervical lymphadenopathy. Her cervical lymph node biopsy revealed histiocytic infiltration showing erythrophagocytosis without marked fibrosis in the capsular and pericapsular areas and distension of sinusoids. After 6 cycles of CHOP (Cyclophosphamide, Adriamycin, Vincristine, and Prednisolone) chemotherapy, cervical and retroperitoneal lymphadenopathy was completely disappeared and according to the resolution of lymphadenopathy hemolytic anemia was also improved.

A Case of Segmental Ischemic Colitis Associated with Nonsteroidal Antiinflammatory Drugs / 대한류마티스학회지

Acute colonic ischemia is the most common form of gastrointestinal ischemia. The majority of cases of non-occlusive ischemic colitis are associated with severe congestive heart failure with low cardiac output, or disease states resulting in dehydration, or the splanchnic vasoconstrictive effect of some dedications. Reactive splanchnic vasoconstriction is responsible for nonocclusive ischemic colitis. The authors report a case of 37-year-old man, who had a history of 8-year gout and no evidence of heart disease or severe dehydration and developed segmental ischemic colitis during nonsteroidal antinflammatory drug treatment, which ultimitely progressed to transmural infacrction, therby undergone extended right hemicolectomy

A Case of Churg - Strauss Syndrome: Presented as Mimic of Rheumatoid Arthritis / 대한류마티스학회지

Churg-Strauss syndrome(CSS) or allergic angiitis and granulomatosis is a disorder characterized by pulmonary and systemic small-vessel vasculitis, extravascular granulomas, and hypereosinophilia. It occurs in individuals with asthma and allergic rhinitis. The diagnosis of CSS is made on the basis of clinical and pathologic features. According to 1990 American College of Rheumatology(ACR) criteria for the classification of CSS, 6 criteria were developed. The presence of 4 or more of these criteria yielded a sensitivity of 85% and a specificity of 99. 7%. We describe a case of CSS in a 62-year-old female who met all of 1990 ACR criteria, but presented as like a as rheumatoid arthritis initially. Clinical symptoms, laboratory and roentgenographic findings gradually responded to high dose prednisolone treatment and resolved 3 weeks later. After discharge, she has been treated with oral prednisolone in a tapering course. Although polyarthritis with eosinophilia, vasculitis, and neuropathy are clinical manifestations of rheumatoid arthritis, those maniestations frequently occur during the vasculitic phase of the CSS. This case suggests that thorough differentiation of extra-articular manifestations of RA from clinical manifestations of CSS is considered when we meet a patient who have polyarthritis and vasculitis.

Acute Myeloid Leukemia with Trisomy 9 Following Chemotherapy of Non-Hodgkin's Lymphoma / 대한암학회지

A 56-year-old male patient with non-Hodgkin's lymphoma achieved complete remission in July 1994 after receiving MACOP-B chemotherapy. 29 months after treatment, acute myeloid leukemia (AML, FAB subtypes M4) with trisomy 9 was developed. To our knowledge this is the first report of therapy-related AML with trisomy 9.