• Parasites, Hosts and Diseases
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• v.62 no.1
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• pp.85-97
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• 2024

This study aimed to describe the morphological and molecular characteristics of Paralecithodendrium longiforme (Digenea: Lecithodendriidae) adults and cercariae isolated in Thailand. Adult flukes were isolated from the Chinese pipistrelle bat (Hypsugo sp.), and cercariae were detected in the viviparid snail (Filopaludina martensi martensi) from Chiang Mai province. The morphological characteristics were observed and described using conventional methods, and the molecular characteristics with internal transcribed spacer 2 (ITS2) and 28S rDNA gene sequences. The adult flukes were fusiform, 0.84-0.98 mm in length, and 0.37-0.49 mm in width, and were distinguishable from other species by the presence of longitudinal uterine coils. The cercariae were nonvirgulate xiphidiocercariae, with the oral sucker bigger than the acetabulum, the tail without fin fold, a body size of 117.5-138.3×48.3-52.2 ㎛, and a tail size of 100.7-103.7×15.0-18.9 ㎛. Molecular studies revealed that the adults and cercariae shared 99.3% (ITS2) and 99.6% (28S rDNA) homology with each other. They were phylogenetically close to P. longiforme with an identity of 94.5% for ITS2 and 98.7% for 28S rDNA. This study provides new information on the natural definitive host and first intermediate host of P. longiforme in Thailand. The discovery of its cercarial stage in Filopaludina snails highlights the importance of monitoring the associated second intermediate host and prevention and control of this potentially zoonotic trematode.

• The Korean Journal of Mycology
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• v.51 no.3
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• pp.251-257
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• 2023

We isolated fungi from the rhizosphere of Fallopia sachalinensis in Dokdo islands. Morphological and molecular characters, based on the internal transcribed spacer (ITS), and partial large subunit (LSU) or partial beta-tubulin genes, were used to identify the isolated fungi. The results revealed the fungi isolated from the Fallopia rhizosphere to be Penicillium striatisporum and Gongronella sichuanensis. Given that these species have never previously been recorded in Korea, we have described the morphological and molecular characteristics of these fungi in this study.

• The Korean Journal of Mycology
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• v.51 no.3
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• pp.179-190
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• 2023

Grapevine downy mildew, caused by Plasmopara viticola, significantly damages vineyards and is one of the most devastating diseases affecting cultivated grapes worldwide. In this study, we characterized the phenotypic and molecular traits of 11 P. viticola isolates from four grape-growing regions in South Korea. Additionally, we investigated the diversity of pathogenicity among these isolates and conducted an assay to evaluate the response of grape cultivars to P. viticola infection. Lemon-shaped sporangia were identified in the collected isolates, which released zoospores into the suspension at room temperature. Within a few hours of inoculation, the zoospores developed germ tubes. We tested 11 P. viticola isolates for pathogenicity in 845 grape cultivars to screen for grape host resistance to downy mildew infection. Among the tested isolates, JN-9 showed the highest virulence. Grape cultivars displayed varying phenotypic reactions to P. viticola infection: approximately 7% were highly susceptible, 41% were susceptible, 20% were moderately susceptible, 8% were resistant, and 24% exhibited extreme resistance. Phylogenetic analysis based on four genomic regions (internal transcribed spacer 1 [ITS1], actin, beta-tubulin, and cytochrome c oxidase II) revealed a close evolutionary relationship among all the Korean isolates, forming a single monophyletic lineage. Notably, these isolates showed greater similarity to European isolates than to American isolates. This comprehensive study contributes to a deeper understanding of the identity and behavior of P. viticola, which is crucial for developing effective resistance strategies against this pathogen in grape cultivars cultivated in South Korea.

• The Plant Pathology Journal
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• v.40 no.2
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• pp.171-191
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• 2024

Identification of Helicotylenchus species is very challenging due to phenotypic plasticity and existence of cryptic species complexes. Recently, the use of rDNA barcodes has proven to be useful for identification of Helicotylenchus. Molecular markers are a quick diagnostic tool and are crucial for discriminating related species and resolving cryptic species complexes within this speciose genus. However, DNA barcoding is not an error-free approach. The public databases appear to be marred by incorrect sequences, arising from sequencing errors, mislabeling, and misidentifications. Herein, we provide a comprehensive analysis of the newly obtained, and published DNA sequences of Helicotylenchus, revealing the potential faults in the available DNA barcodes. A total of 97 sequences (25 nearly full-length 18S-rRNA, 12 partial 28S-rRNA, 16 partial internal transcribed spacer [ITS]-rRNA, and 44 partial cytochrome c oxidase subunit I [COI] gene sequences) were newly obtained in the present study. Phylogenetic relationships between species are given as inferred from the analyses of 103 sequences of 18S-rRNA, 469 sequences of 28S-rRNA, 183 sequences of ITS-rRNA, and 63 sequences of COI. Remarks on suggested corrections of published accessions in GenBank database are given. Additionally, COI gene sequences of H. dihystera, H. asiaticus and the contentious H. microlobus are provided herein for the first time. Similar to rDNA gene analyses, the COI sequences support the genetic distinctness and validity of H. microlobus. DNA barcodes from type material are needed for resolving the taxonomic status of the unresolved taxonomic groups within the genus.

• Journal of the Korean Wood Science and Technology
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• v.52 no.4
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• pp.343-362
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• 2024

Eurycoma longifolia (pasak bumi) is a popular medicinal plant in Indonesia and is widely used in various products. Its high economic value has caused illegal harvesting and product falsification. Using molecular techniques, the authentication and traceability of E. longifolia derivatives can be controlled to ensure consumer safety. Therefore, this study aimed to authenticate the products and derivatives of E. longifolia (pasak bumi) produced, marketed, and consumed in Indonesia using molecular identification techniques. Genomic DNA from 37 leaf samples collected from the Sumatran mainland and the Riau Islands and six E. longifolia products were amplified and sequenced using trnL-trnF and internal transcribed spacer (ITS) regions. The results revealed that all leaf samples were indeed E. longifolia based on the markers used, with the six products, only the herbal tea product (sample code TCPB) was most likely derived from E. longifolia based on the two regions, suggesting that not all products labelled as E. longifolia in the market are authentic. The results also indicated that several other plants species are used as substitutes or adulterants, including Simaba spp., Simarouba spp., Homalolepis spp., Vernonia gigantea, Elephantopus scaber, Gymnanthemum amygdalinum, Cyanthillium spp., Potentilla lineata, Ailanthus altissima, Geijera paniculata, Hannoa chlorantha, and Dalbergia spp. Klebsiella pneumoniae bacteria were also identified in this study on the outer wooden cup of E. longifolia products. Therefore, this molecular approach is effective in identifying the authenticity of E. longifolia products, with trnL-trnF and ITS as the recommended DNA markers.

• The Korean Journal of Mycology
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• v.52 no.2
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• pp.145-153
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• 2024

While investigation of the fungal diseases on apples collected from Cheongsong-gun and Bonghwa-gun in Gyeongbuk province, Korea, between August and September 2023 isolated five fungal strains from fruits with sooty blotch and flyspeck (SBFS) disease. The strains were designated as KNUF-23-CS02, KNUF-23-CS-06, KNUF-23-CS12, KNUF-23-BH01, and KNUF-23-BH03. When grown on potato dextrose agar and 2% water agar, the cultural characteristics of the strains were similar to those previously reported characteristics of Peltaster fructicola Pf001. The strains produced monoblastic, hyaline conidiogenous cells; the conidia were hyaline, unicellular, cylindrical to ovoidal, and 3.5-7×1.7-3.9 and 4.0-6.6×1.8-3.2 μm in size on synthetic nutrient-poor agar or water agars, respectively. Secondary conidia production by microcyclic conidiation and budding was observed. The KNUF-23-BH03 strain was shown to cause SBFS symptoms similar to those observed on the apples in the pathogenicity test. Molecular phylogenetic analyses were conducted based on the isolated species sequences of the internal transcribed spacer region, nuclear large ribosomal DNA subunit, and mitochondrial small ribosomal RNA subunit gene. The five strains were clustered with Peltaster fructicola Pf001. Based on the cultural and morphological characteristics and phylogenetic analysis, the five strains were identified as Peltaster fructicola, which has not been previously reported in Korea.

• ALGAE
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• v.39 no.3
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• pp.129-147
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• 2024

The species complex Mesodinium rubrum / major, common red tide-forming ciliates, has been intensively studied with regards to its ecological roles in global marine ecosystems and the evolutionary aspects of its "stolen" organelles (kleptoplasty and karyoklepty). Nonetheless, the taxonomy of the species within the complex remains unclear. A new marine Mesodinium species isolated from Gomso Bay, Korea, was cultivated under mixotrophic conditions by providing Teleaulax amphioxeia, a red cryptomonad, as prey. Cells of the new isolate consisted of two portions separated by two types of polykinetids. The number of polykinetid associated with the equatorial ciliary belt was approximately 38, and each consisting of two rows of up to 18 alternating kinetosomes each. There was an equal number of cirral polykinetids, each consisting of 16 kinetosomes organized into four longitudinal rows having five, five, four, and two kinetosomes, respectively (in anti-clockwise direction). The two kinds of kinetids and their associated microtubules and fibers were structurally similar to those of M. rubrum from Denmark. However, the Korean Mesodinium species was characterized by its broad posterior portion, 20-22 tentacles, and a cytopharyngeal annulus. Molecular phylogeny based on internal transcribed spacer sequences placed the Korean isolate in clade B of the M. rubrum / major species complex, rather than in clade F representing the neotype of M. rubrum. Based on morphological, ultrastructural, and molecular data, we propose the Korean strain as a new marine Mesodinium species, M. annulatum.

• International Journal of Industrial Entomology and Biomaterials
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• v.48 no.3
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• pp.124-138
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• 2024

The International Union for Conservation of Nature and the Korean Red Data Book both categorize the dragon swallowtail Sericinus montela Grey, 1852 (Lepidoptera: Papilionidae) as a vulnerable insect. In South Korea, the main reason for this categorization is habitat destruction and deterioration, along with limited distribution mainly to the eastern region of South Korea, particularly to Gangwon-do and Gyeongsangbuk-do. Considering much of the information is older than ten years the renewed survey to estimate distributional stability is required, particularly under global warming. In addition, the population genetic diversity and isolation of S. montela, which is important information when seeking to evaluate its vulnerability, is not yet known. In this study, we visited 38 habitable sites, consisted of 15 sites with the previous record for the sightings of the species and 23 sites without such record. Moreover, nuclear ribosomal internal transcribed spacer region was sequenced for 56 individuals collected from seven sites. We observed S. montela at 20 sites, consisted of 11 recorded and 9 new sites in seven provinces, excluding Jeollanam-do and Jeju-do. Finding of the species in 9 new sites and location of the 4 in western region, which has a rare previous record are promising. However, failure to observe in 4 recorded sites and an extremely low observed number in new sites (5.3 vs. 17.6 individuals per site on average) is not optimistic. Population genetic data partially corroborate with the field observation data, showing that the populations in western region have lower genetic diversity and intermittent genetic isolation compared to those in eastern region. Taken these together, we suggest that S. montela should be remained as a vulnerable insect. However, more extensive field monitoring and co-dominant molecular data are required to verify this conclusion.

• The Korean Journal of Mycology
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• v.46 no.3
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• pp.281-294
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• 2018

Molecular analysis using the internal transcribed spacer region sequences revealed that the strains used in this study, which were formerly identified as Panellus serotinus, are Panellus edullis. After Universal Fungal PCR Fingerprinting (UFPF) analysis, eight strains of P. edulis were divided into two groups. We conducted fundamental research on mycelial growth and sawdust cultivation to understand the cultural characteristics of eight wild P. edulis strains collected from Korean forests. All strains showed faster and denser mycelial growth on potato dextrose agar (PDA) than on other media (malt extract agar, Sabouraud dextrose agar). Optimal conditions for mycelial growth were: $20^{\circ}C$ on PDA, $25^{\circ}C$ on potato dextrose broth (PDB), and pH 5~8 on PDB at $25^{\circ}C$. Two strains (NIFoS 2407, 3993) were selected as excellent strains based on mycelial growth and density on PDA. NIFoS 2792 showed high cellulase activities on carboxymethyl cellulose (CMC) agar, and NIFoS 2387 and 2804 exhibited high laccase activities on ABTS-containing agar media. The mycelial growth of P. edulis was the fastest on Quercus acutissima and Q. mongolica sawdust media, and mycelial density was the highest on Quercus spp. sawdust-containing media. Sawdust cultivation of P. edulis was successful. The conditions were 80~85 days of cultivation period after spawn inoculation, 10~11 days for primordial formation at $17{\sim}18^{\circ}C$, and 15~20 days for fruiting growth. NIFoS 2804 and 3993 were selected as good strains in terms of cultivation period and mushroom production. These results could be useful for the artificial cultivation of P. edulis.

• Asian Journal of Turfgrass Science
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• v.20 no.1
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• pp.65-76
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• 2006

Scz1, an isolate of Sclerotinia homoeocarpa, was recently reported as a novel pathogen responsible for dollar spot disease in Zoysiagrass, a warm season turfgrass. Scz1 possessed different characteristics on mycelial pigment, mycelial affinity and host pathogenecity compared to those of Scb1, a typical isolate, obtained from creeping bentgrass, a cool season turfgrass. In this study, only three isolates, Scz1, Scz2(another analogous isolate of Sclerotinia homoeocarpa from zoysiagrass), and Scb1, were examined at the molecular level using the internal transcribed spacer(ITS) and random amplified polymorphic DNA(RAPD) assays to verify their identification and genetic variation. As a result of ITS assay, partial ITS sequences of three isolates showed 94-97% similarity with a standardized ITS sequence of S. homoeocarpa registered on BLAST. In the analysis of RAPD, range value through similarity matrix was 0.167 between Scz1 and Scb1, 0.139 between Scz2 and Scb1, and 0.713 between Scz1 and Scz2, respectively. Furthermore, tendegram analysis indicated that Scz1 and Scz2, unlike Scb1, were clustered together as accompanying a high genetic similarity. In in vitro fungicide bioassay, $EC_{50}$ value representing the sensitivity degree to propiconazole, a well-known fungicide for dollar spot disease, was 0.012 ${\mu}g/ml$ for Sczl, 0.003 ${\mu}g/ml$ for Scz2, and 0.030 ${\mu}g/ml$ for Scb1. From all data taken, we concluded that both Scz1 and Scz2 belonged to one group of S. homoeocarpa, since they exhibit the same host range and high level of genetic similarity, whereas their chemical competences to a fungicide were different. This study would provide further approach for assessing genetic diversity of S. homoeocarpa isolates as well as characterizing individual isolate against chemical exposure.