• Research in Plant Disease
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• v.22 no.2
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• pp.116-121
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• 2016

In 2015, stem blight of Rubus crataegifolius was observed in Pohang, Korea. The symptoms began as dark red spots in the stem, which led to stem blight, then leaf blight, and eventually resulted in death. A fungal isolate was obtained from a symptomatic stem and incubated on a potato dextrose agar plate. The isolated fungus produced white, cloudy mycelia turned black in 3 days. Based on the morphological characteristics, the causal fungus was assumed to be Botryosphaeria sp. A pathogenicity test was conducted according to Koch's postulates. To identify the causal agent, the combined sequence of the internal transcribed spacer, ${\beta}$-tubulin, and translation elongation factor $1{\alpha}$ genes were used for phylogenetic analysis. Approximately 1,200 bp of the combined sequence clearly suggested that the isolated pathogen was Botryosphaeria parva. This is the first report on stem blight in R. crataegifolius caused by B. parva in Korea.

• Mycobiology
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• v.44 no.4
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• pp.319-324
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• 2016

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.

• Mycobiology
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• v.48 no.6
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• pp.495-500
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• 2020

Leaf spot on lemon balm is frequently observed in Korea, causing considerable damage to crops. In 2014 and 2015, the occurrence of leaf spot was observed in several production greenhouses at Suwon, Gongju, and Namwon in Korea. Symptoms on lower leaves initially developed as small, distinct, discolored lesions, which enlarged progressively turning into dark brown, angular spots surrounded by purplish-brown margins. Based on the morphological characteristics and sequence analysis of actin (ACT), translation elongation factor 1-alpha (EF-1α), internal transcribed spacer (ITS), 28S nrDNA (LSU), and RNA polymerase II second largest subunit (RPB2), the fungus associated with the lemon balm leaf spot was determined as Septoria melissae. To the best of our knowledge, this is the first report of lemon balm leaf spot caused by S. melissae in Asia as well as in Korea.

• The Korean Journal of Mycology
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• v.51 no.2
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• pp.111-120
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• 2023

Three fungal strains designated as KNUF-23-MG32, KNUF-23-YC8, and KNUF-23-MJ82 were isolated from the abnormal symptomatic apple trees during screening fungal pathogens collected in Jeollanam-do and Gyeongsangbuk-do, Korea. These fungal strains were found to have similar cultural and morphological characteristics close to the genus Botryosphaeria. Morphological characteristics were matched with B. kuwatsukai CBS 135219 but different with B. dothidea KACC 45481 and B. sinensis HMAS 246714^T. Pathogenicity tests of strain KNUF-23-MG32 showed that this strain causes rot in Fuji apples. Molecular phylogenetic analysis based on the sequences of the internal transcribed spacer (ITS) regions, translation elongation factor 1-alpha (TEF1α), and partial β-tubulin (TUB2) showed that these strains are B. kuwatsukai. To the best of our knowledge, this is the first report of an apple ring rot fungus Botryosphaeria kuwatsukai in Korea.

• ALGAE
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• v.31 no.2
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• pp.167-174
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• 2016

Biological response of cells to variable conditions should affect the expression level of certain genes. Quantification of these changes in target genes needs stable internal controls. Real-time quantitative polymerase chain reaction (PCR) has traditionally used reference or ‘housekeeping’ genes, that are considered to maintain equal expression in different conditions, to evaluate changes in target genes between samples and experimental conditions. Recent studies showed that some housekeeping genes may vary considerably in certain biological samples. This has not been evaluated in red algae. In order to identify the optimal internal controls for real-time PCR, we studied the expression of eleven commonly used housekeeping genes; elongation factor 1-alpha, glyceraldehyde-3-phosphate dehydrogenase, β-actin, polyubiquitin, 30S ribosomal gene, 60S ribosomal gene, beta-tubulin, alpha-tubulin, translation initiation factor, ubiquitin-conjugating enzyme, and isocitrate dehydrogenase in different life-history stages of Bostrychia moritziana. Our results suggest that glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and 30S ribosomal gene, have the most stable gene expression levels between the different life history stages (male, female, carposporophyte, and tetrasporophyte), while the other genes are not satisfactory as internal controls. These results suggest that the combinations of GAPDH and 30S would be useful as internal controls to assess expression level changes in genes that may control different physiological processes in this organism or that may change in different life history stages. These results may also be useful in other red algal systems.

• Research in Plant Disease
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• v.17 no.2
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• pp.216-221
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• 2011

A representative isolate KU53 of the predominant Penicillium species was obtained from rice samples from rice processing complexes of National Agricultural Cooperative Federation in Korea. In this study, isolate KU53 was identified by its morphological and molecular characteristics. The macro- and microscopic characteristics of isolate KU53 were compared with the P. fellutanum reference isolate KCTC16913 on different media; isolate KU53 was generally identical to those of the reference isolate KCTC16913. In a molecular-based identification, the ${\beta}$-tubulin and translation elongation factor 1-alpha sequences of isolate KU53 was most closely related to those of P. fellutanum. Thus, isolate KU53 from stored rice could be identified as P. fellutanum, some isolates of which are known to produce mycotoxin-related metabolites. To our knowledge, this is the first detection of P. fellutanum from stored rice in Korea.

• The Plant Pathology Journal
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• v.28 no.4
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• pp.341-356
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• 2012

Shiitake (Lentinula edodes) is the most economically important cultivated mushroom, but yields are impacted by its competitor, Trichoderma spp. We previously found two unidentified Trichoderma species growing in bedlogs and sawdust shiitake media in Korea. Here, we identify and re-describe those two species based on molecular sequence data, morphology, and culture characteristics. Well-supported clades based on phylogenetic analyses of internal transcribed spacer, translation elongation factor 1-${\alpha}$, and RNA polymerase subunit II sequences grouped one of the unidentified Trichoderma spp. with Hypocrea pseudogelatinosa and the other with Hypocrea pseudostraminea, and their morphologies matched well with the original descriptions of the two Hypocrea species. This study reports the first phylogenetic analyses of H. pseudogelatinosa and Japanese strains of H. pseudostraminea. Based on the phylogenetic results, we redescribed these two species using modern taxonomic concepts in Hypocrea/Trichoderma.

• Mycobiology
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• v.47 no.3
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• pp.340-345
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• 2019

An 82-year-old man with diabetes was admitted to the emergency department with a third-degree burn on his left leg. The deep swab specimen from his left leg was cultured on Sabouraud dextrose agar without cycloheximide and incubated at $25^{\circ}C$ for 5 days. On the basis of morphological characteristics and multigene phylogenetic analyses of the internal transcribed spacer region of ribosomal DNA and partial fragments of beta-tubulin and translation elongation factor 1-alpha, the causal agent of fungal skin infection was identified as Bisifusarium delphinoides, which was newly introduced by accommodating a Fusarium dimerum species complex. Thus, we describe here the first case of skin infection caused by B. delphinoides on a burn patient with diabetes mellitus based on morphological observation and molecular analysis.

• Mycobiology
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• v.50 no.5
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• pp.302-316
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• 2022

Many Apiospora species have been isolated from bamboo plants - to date, 34 bambusicolous Apiospora species have been recorded. They are known as saprophytes, endophytes, and plant pathogens. In this study, 242 bambusicolous Apiospora were isolated from various bamboo materials (branches, culms, leaves, roots, and shoots) and examined using DNA sequence similarity based on the internal transcribed spacer, 28S large subunit ribosomal RNA gene, translation elongation factor 1-alpha, and beta-tubulin regions. Nine Apiospora species (Ap. arundinis, Ap. camelliae-sinensis, Ap. hysterina, Ap. lageniformis sp. nov., Ap. paraphaeosperma, Ap. pseudohyphopodii sp. nov., Ap. rasikravindrae, Ap. saccharicola, and Ap. sargassi) were identified via molecular analysis. Moreover, the highest diversity of Apiospora was found in culms, and the most abundant species was Ap. arundinis. Among the nine Apiospora species, two (Ap. hysterina and Ap. paraphaeosperma) were unrecorded in Korea, and the other two species (Ap. lageniformis sp. nov. and Ap. pseudohyphopodii sp. nov.) were potentially novel species. Here, we describe the diversity of bambusicolous Apiospora species in bamboo organs, construct a multi-locus phylogenetic tree, and delineate morphological features of new bambusicolous Apiospora in Korea.

• The Korean Journal of Mycology
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• v.50 no.4
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• pp.319-329
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• 2022

In July 2020, wilting symptoms were observed among adzuki bean plants (Vigna angularis var. angularis L.) in the fields in Yeosu, Korea. Infected plants showed yellowing of leaves, browning inside the stems, splitting of stem bark, and wilting. When these plants were uprooted, their roots were found to be brown. The fungal pathogens NC20-737, NC20-738, and NC20-739 were isolated from symptomatic stem and root tissues. These pathogens were identified as a Fusarium fujikuroi species complex based on their morphological characteristics. Molecular identification was performed using the DNA sequence of translation elongation factor 1 alpha and the RNA polymerase II second largest subunit regions. The nucleotide sequences of all three isolates were similar to the F. fujikuroi reference isolates NRRL 13566 and NRRL 5538 of the National Centre for Biotechnology Information GenBank. A pathogenicity test was conducted by the soil inoculation method with cornmeal sand inoculum. Approximately 3 weeks after inoculation, symptoms were observed only in the inoculated adzuki bean seedlings. To the best of our knowledge, this is the first report of Fusarium root rot caused by F. fujikuroi in adzuki beans, both in Korea and worldwide.