• Mycobiology
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• v.50 no.4
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• pp.213-218
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• 2022

The genus Mitrula (Mitrulaceae, Helotiales), as also known as swamp beacons, inhabits submerged, decaying vegetation in standing or decaying needles, twigs, leaves, and shallow water. They play an important role in carbon cycling in some freshwater ecosystems. In the herbarium of the Korea National Arboretum (KH), seven Mitrula specimens were collected during mushroom forays in the period from 2019 to 2021. The Korean collections were found to be macromorphologically closely related to M. paludosa and M. elegans, but micro-morphologically they could be distinguished by characteristics of slightly narrower asci and aseptate ascospores. Our molecular phylogenetic analyses of the internal transcribed spacer (ITS) and 28S rDNA regions also revealed that our specimens were related to M. paludosa and M. elegans, but formed a distinct clade. Based on these results, we reported our specimens as new to science and discussed the phylogeny and diversity of Mitrula species.

• Mycobiology
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• v.50 no.4
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• pp.244-253
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• 2022

Trichoderma fungi have been intensively studied for mycoparasitism, and the latter is closely related to their cell-wall degrading enzymes including chitinase. Here, we studied marine-derived Trichoderma spp., isolated from distinct sources and locations, for chitinolytic and antifungal activity. Based on morphological and phylogenetic analyses, two strains designated GJ-Sp1 and TOP-Co8 (isolated from a marine sponge and a marine alga, respectively) were identified as Trichoderma bissettii. This species has recently been identified as a closely related species to Trichoderma longibrachiatum. The extracellular crude enzymes of GJ-Sp1 and TOP-Co8 showed activities of chitobiosidase and b-N-acetylglucosaminidase (exochitinase) and chitotriosidase (endochitinase). The optimum chitinolytic activity of the crude enzymes was observed at 50 ℃, pH 5.0, 0-0.5% NaCl concentrations, and the activities were stable at temperatures ranging from 10 to 40 ℃ for 2 h. Moreover, the crude enzymes showed inhibitory activity against hyphal growth of two filamentous fungi Aspergillus flavus and Aspergillus niger. To the best of our knowledge, this is the first report of the chitinolytic and antifungal activity of T. bissettii.

• Mycobiology
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• v.50 no.5
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• pp.326-344
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• 2022

The fungal-like family Saprolegniaceae (Oomycota), also called "water mold," includes mostly aquatic saprophytes as well as notorious aquatic animal pathogens. Most studies on Saprolegniaceae have been biased toward pathogenic species that are important to aquaculture rather than saprotrophic species, despite the latter's crucial roles in carbon cycling of freshwater ecosystems. Few attempts have been made to study the diversity and ecology of Saprolegniaceae; thus, their ecological role is not well-known. During a survey of oomycetes between 2016 and 2021, we investigated the diversity and distribution of culturable Saprolegniaceae species in freshwater ecosystems of Korea. In the present study, members of Saprolegniaceae were isolated and identified at species level based on their cultural, morphological, and molecular phylogenetic analyses. Furthermore, substrate preference and seasonal dynamics for each were examined. Most of the species were previously reported as animal pathogens; however, in the present study, they were often isolated from other freshwater substrates, such as plant debris, algae, water, and soil sediment. The relative abundance of Saprolegniaceae was higher in the cold to cool season than that in the warm to hot season of Korea. This study enhances our understanding of the diversity and ecological attributes of Saprolegniaceae in freshwater ecosystems.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.115.2-116
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• 2003

Complete genomic nucleotide sequence of Daphe virus S (DVS), a member of the genus Carlavirus, causing leaf distortion and chlorotic spot disease symptoms in daphne plants, has been determined in this study. The genome of DVS contained six open reading fames coding for long viral replicase, triple gene block, 36 kDa viral coat protein (CP) and 12 kDa from the 5' to 3' ends, which is a typical genome structure of carlaviruses. Two Korean isolates of DVS isolates were 98.1％ and 93.6％ amino acid identical in the CP and 12kDa, respectively. The CP gene of DVS shares 25.2-55.2％ and 42.9-56.1％ similarities with that of 19 other carlaviruses at the amino acid and nucleotide levels, respectively. The 3'-proximal 12 kDa gene of DVS shares 20.2-57.8％ amino acid identities with that of 18 other members of the genus. The 3' noncoding region of DVS consists of 73 nucleotides with long excluding poly A tract, and shares 69.1-77.1％ identities to the known carlaviruses. In the phylogenetic analyses of the two proteins, DVS was closely related to Helenium virus S and Chrysanthemum virus B. This is the first complete sequence information for the DVS, and further confirms the classification of DVS as a distinct species of the genus Carlavirus.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.693-702
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• 2021

The aim of this study was to analyze the genetic diversity and distance of the Korean native black goat line. Thus far, this Korean native black goat line has not been studied intensively, especially in genetic diversity and relationship studies in comparison with other breeds. In total, eleven microsatellite (MS) markers were used to evaluate alleles from 391 Korean native black goats and foreign hybrid animals. The genetic diversity index was evaluated based on the allele distributions. Four Korean native black goat lines showed expected ranges of observed heterozygosity, expected heterozygosity, and polymorphism information content (PIC) values for use in genetic diversity research (0.509 - 0.643, 0.434 - 0.623 and 0.356 - 0.567). Lines from the Korean native black goat and foreign hybrid were clearly separated according to principal coordinates analysis (PCoA), phylogenetic tree and tended to be clustered in each Korean native black goat line. Thus, this study can be used for analyzing the genetic relationships between Korean native black goats and foreign breeds for line preservation and for fundamental information to determine breed improvement strategies.

• Animal Systematics, Evolution and Diversity
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• v.39 no.3
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• pp.99-113
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• 2023

The nudibranch is one of the most colorful gastropod species found in oceans worldwide. Unlike many other gastropod groups, the nudibranch loses an external shell in the adult stage, but instead develops various chemical defense systems. More than 2,500 nudibranch species have been reported worldwide, and 73 species are currently recorded in Korean waters. In this study, we present morphological descriptions, DNA barcode information of mtDNA cox1 sequence, and taxonomic review for five nudibranch species: Apata pricei (MacFarland, 1966), Doto rosacea Baba, 1949, Janolus toyamensis Baba and Abe, 1970, Polycera abei (Baba, 1960), and Trinchesia sibogae (Bergh, 1905). Of these, we also provide in-depth discussion of taxonomic issue of A. pricei that was previously subdivided into two subspecies, A. pricei pricei and A. pricei komandorica. Our morphological examination and molecular analyses of the mtDNA cox1 sequences indicate that these two subspecies are not taxonomically warranted. The phylogenetic information for the other nudibranch species from mtDNA cox1 sequence analysis is also included, providing a molecular basis for species identification and inferring their local phylogenies within each of the species groups discussed herein.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.47-47
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• 2020

In this study, we aimed to study carnation italian ringspot virus (CIRV) in Erigeron annuus (L.) Pers. in Bonghwa County, Korea. The collected samples showed mosaic and malformation symptoms. To identify the virus species, we performed high-throughput sequencing, reverse transcription polymerase chain reaction, and cloning. The virus was confirmed to be an unreported species, and therefore we performed genome sequencing of the samples. The complete genome was 4,746 nucleotides in length. The CIRV contained five open reading frames (ORFs), and it showed the typical features of members of the genus Tombusvirus. Phylogenetic analyses revealed that ClRV isolates had the highest nucleotide identities with the CZ isolate (95.89%) from Korea. In recent years, these viruses have sporadically been reported in floral scent and medicinal plants. This research found the first natural host infected with CIRV, and provides baseline information to determine the correlation between weeds and crops.

• The Korean Journal of Mycology
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• v.51 no.4
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• pp.491-504
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• 2023

To explore fungal diversity in orchard soil where fire-blighted apple trees are buried, we collected soil samples from apple orchards in Chungju, Korea. Fungal isolates were obtained from DG18 agar and identified at the species level based on morphological features and phylogenetic analyses. The colony characteristics and microstructures were examined using a light microscope and a scanning electron microscope after culturing on potato dextrose agar (PDA), malt extract agar (MEA), Czapek yeast agar (CYA), and oatmeal agar (OA) The PCR-amplified products of the ITS1-5.8S-ITS2 region and 28S large subunit of the nuclear ribosomal RNA gene, as well as partial sequences of the β-tubulin, calmodulin, and translation elongation factor 1-α genes were sequenced and analyzed phylogenetically. Seven previously unknown fungal species were explored in Korea. All samples, including Aspergillus aureolatus, Botryotrichum atrogriseum, Dactylonectria novozelandica, Fusarium denticulatum, Paecilomyces tabacinus, Sarcopodium tibetense and Talaromyces stollii, had ascomycetes. Herein, we report their descriptions and features.

• Journal of Species Research
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• v.13 no.1
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• pp.10-31
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• 2024

In this study, 11 strains of epilithic cyanobacteria belonging to six unrecorded species in Korea were isolated from gravel submerged in freshwater of seven collection sites in Korea. The morphological characteristics of the six species isolated in this study were consistent with the type strain of each species, and the similarity of the 16S rRNA gene sequences with the type strain of each species were 98.8-100%. In the phylogenetic tree using the 16S rRNA gene sequences, the 11 strains of these six species formed the same cluster as the strains of each species. The habitat of each previously reported species is mainly the soil surface, but all Korean strains appeared from the gravel submerged in freshwater. As a result of the morphological, ecological, and molecular analyses, these six species of cyanobacteria were identified as Geminocystis papuanica, Allocoleopsis franciscana, Ancylothrix terrestris, Klisinema persicum, Scytolyngbya timoleontis, and Shackletoniella antarctica, which were added as newly recorded species in Korea.

• Journal of Mushroom
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• v.22 no.2
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• pp.37-47
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• 2024

Fluorescent bacteria were isolated from sporocarps that browned into various mushrooms during survey at places of the production in Korea. We examined the pathogenicity, biodiversity, and genetic characteristics of the 19 strains identified as Pseudomonas tolaasii by sequence analysis of 16S rRNA and White Line Assay. The results emphasize the importance of rpoB gene system, fatty acid profiles, specific and sensitive PCR assays, and lipopeptide detection for the identification of P. tolaasii. As a result of these various analyses, 17 strains (CHM03~CHM19) were identified as P. tolaasii. The phylogenetic analysis based on the 16S rRNA gene showed that all strains were clustered closest to P. tolaasii lineage, two strains (CHM01, CHM02) were not identified as P. tolaasii and have completely different genetic characteristics as a result of fatty acids profile, specific and sensitive PCR, lipopetide detection, rpoB sequence and REP-PCR analysis. Pathogenicity tests showed 17 strains produce severe brown discolouration symptoms to button mushrooms and watersoaking of sporophore tissue within three days after inoculation. But two strains did not produce discolouration symptoms. Therefore, these two strains will be further investigated for correct species identification by different biological and molecular characteristics.