• The Korean Journal of Mycology
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• v.38 no.1
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• pp.40-47
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• 2010

To investigate genetic relationships either interspecies or intraspecies of 14 Korean Phytophthora species, sequence analyses of nuclear DNA (ypt gene and rDNA-IGS region) and mitochondrial DNA (Cox gene, $\beta$-tubuline gene, and EF1A gene) were performed. All of 14 Korean Phytophthora species clearly clustered into foreign isolates of each species. These Korean isolates in Phytophthora species also showed no correlation between molecular classification and morphological classification like as in case of foreigners. P. palmivora KACC 40167 reported previously from genetic groups of Phytophthora species in Korea was not consistent with the classification system, and therefore was required re-examination for the genetic group analysis. Korean isolates of P. drechsleri KACC 40195 showed very close relationship with P. cryptogea KACC 40161 above 94% bootstrap value in P. cryptogea-P. drechsleri complex group. Identification of these isolates is still unclear, because P. cryptogea and P. drechsleri were not differentiated in this study. On the other hand, it was required to unify species for these two species, since P. parasitica and P. nicotianae were clustered into a group on the level of 99 to 100% sequence homology. Comparing to the sequences of foreigners, Korean isolates were newly divided to ten groups in the phylogenic system. These results could be prepared useful informations to understand genetic diversity of Phytophthora species in Korea.

• The Korean Journal of Mycology
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• v.46 no.4
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• pp.369-374
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• 2018

The fungal strain KNU16-004 was isolated from a field soil sample collected in Seoul. The isolate was identified as Leptosphaerulina australis based on morphological characterization and phylogenetic analysis using the internal transcribed spacer (ITS), large subunit (LSU) rDNA regions, and ${\beta}-tubulin$ (Tub2). This is the first report of Leptosphaerulina australis in Korea.

• Mycobiology
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• v.50 no.3
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• pp.155-165
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• 2022

Penicillium vietnamense sp. nov. was isolated from Nha Trang Bay, Vietnam in June 2017. It is phylogenetically distinct from the sister species of Penicillium section Charlesia series Indica based on multi-locus sequence typing results using internal transcribed spacer, large subunit ribosomal RNA, b-tubulin, calmodulin, and RNA polymerase II second largest subunit regions. It showed strong growth on Czapek yeast autolysate agar at 37 ℃, a strong acid production on Creatine sucrose agar, and produced short stipes, small vesicles, and subglobose to globose conidia delicately roughened with very short ridges. As the first novel marine fungi species described from Vietnam and discovered in a unique environment, the data could be significant for understanding the taxonomy and geographical distribution of marine fungi in tropical coastal systems such as Vietnam.

• Mycobiology
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• v.51 no.2
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• pp.72-78
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• 2023

In this study, a fungal strain KNUF-22-025 belonging to the genus Botryotrichum was isolated from the soil in Korea. The cultural and morphological characteristics of this strain differed from those of closely related species. On malt extract agar, strain KNUF-22-025 showed slower growth than most of the related species, except B. domesticum. The conidia size (9.6-21.1×9.9-18.4 ㎛) of strain KNUF-22-025 was larger than those of B. piluliferum, B. domesticum, and B. peruvianum but smaller than those of B. atrogriseum and B. iranicum. Conidiophores in strain KNUF-22-025 (137 ㎛) were longer than those in other closely related species but shorter than those in B. atrogriseum. Multi-locus analysis of molecular markers, such as ITS, 28S ribosomal DNA, RBP2, and TUB2 revealed that strain KNUF-22-025 was distinct from other Botryotrichum species. Thus, this strain is proposed as a novel species based on morphological characteristics along with molecular phylogeny and named Botryotrichum luteum sp. nov.

• 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.

• Korean Journal of Agricultural Science
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• v.45 no.4
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• pp.575-582
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• 2018

Bacterial fruit blotch (BFB) caused by Acidovorax citrulli is a devastating disease found in many cucurbits cultivation fields. The genetic diversity for 29 strains of A. citrulli collected from various cucurbits in South Korea was determined by DNA fingerprinting with a pathogenicity test, multi locus analysis, Rep-PCR (repetitive sequence polymerase chain reaction), and URP (universal rice primers) PCR bands. Two distinct groups (Korean Clonal Complex, KCC1 and KCC2) in the population were identified based on group specific genetic variation in the multi locus phylogeny using six conserved loci and showed a very high similarity with DNA sequences for representative foreign groups [the group I (CC1-1 type) and the group II (CC2-5 type)] widely distributed worldwide, respectively. Additionally, in the case of phaC, a new genotype was found within each Korean group. The KCC1 was more heterogeneous compared to the KCC2. The KCC1 recovered mainly from melons and watermelons (ratio of 6 : 3) and 15 of the 20 KCC2 strains recovered from watermelons were dominant in the pathogen population. Accordingly, this study found that two distinct groups of differentiated A. citrulli exist in South Korea, genetically very similar to representative foreign groups, with a new genotype in each group resulting in their genetic diversity.

• Research in Plant Disease
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• v.21 no.2
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• pp.82-88
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• 2015

Acidovorax citrulli, the causal agent of bacterial fruit blotch, has caused an economically destructive damage in cucurbits cultivation fields worldwide. To consider more effective disease management, 33 A. citrulli isolates collected from various cucurbits in Korea were analysed by multi-locus phylogeny using five conserved loci(16S rRNA, adk, gltA, glyA, pilT). Two distinct groups (KCC1 and KCC2) in the population were identified on the base of group-specific genetic variation. Out of them, the predominant group was KCC2 and both groups included isolates from melon, cucumber and watermelon. Sixty-four percent of KCC1 isolates were recovered from non-watermelon hosts and seventy-two percent of KCC2 isolates from watermelon. This study presented that there was genetic differentiation among A. citrulli population in Korea. Also, these results will be applied as a very useful data in effective disease management.

• ALGAE
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• v.31 no.3
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• pp.219-230
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• 2016

The Euglena deses group are common freshwater species composed of E. adhaerens, E. carterae, E. deses, E. mutabilis, and E. satelles. These species are characterized by elongated cylindrical worm-like cell bodies and numerous discoid chloroplasts with a naked pyrenoid. To understand the cryptic diversity, species delimitation and phylogenetic relationships among members of the group, we analyzed morphological data (light and scanning electron microscopy) and molecular data (nuclear small subunit [SSU] and large subunit [LSU] rDNAs and plastid SSU and LSU rDNAs). Bayesian and maximum likelihood analyses based on the combined four-gene dataset resulted in a tree consisting of two major clades within the group. The first clade was composed of two subclades: the E. mutabilis subclade, and the E. satelles, E. carterae, and E. adhaerens subclade. The E. mutabilis subclade was characterized by a lateral canal opening at the anterior end and a single pellicular stria, whereas the E. satelles, E. carterae, and E. adhaerens subclade was characterized by an apical canal opening at the anterior end of the cell and double pellicular striae. The second clade consisted of 20 strains of E. deses, characterizing by a subapical canal opening at the anterior end and double pellicular striae, but they showed cell size variation and high genetic diversity. Species boundaries were tested using a Bayesian multi-locus species delimitation method, resulting in the recognition of five cryptic species within E. deses clade.

• ALGAE
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• v.35 no.1
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• pp.17-32
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• 2020

Asterochloris is one of the most common genera of lichen phycobionts in Trebouxiophyceae. Asterochloris phycobionts associated with the lichenized fungi Cladonia and Stereocaulon in King George Island (Antarctica) and Morro Chico (Chile), were isolated and then used to establish clonal cultures. To understand the phylogenetic relationships and species diversity of Antarctic Asterochloris species, molecular and morphological data were analyzed by using three microscopy techniques (light, confocal laser and transmission electron) and a multi-locus phylogeny with data from the nuclear-encoded internal transcribed spacer (ITS) rDNA and the actin and plastid-encoded ribulose bisphosphate carboxylase large chain (rbcL) coding genes. Morphological data of three Antarctic strains showed significant species-specific features in chloroplast while molecular data segregated the taxa into distinct three clades as well. Each species had unique molecular signatures that could be found in secondary structures of the ITS1 and ITS2. The species diversity of Antarctic Asterochloris was represented by six taxa, namely, A. glomerata, A. italiana, A. sejongensis, and three new species (A. antarctica, A. pseudoirregularis, A. stereocaulonicola).

• Mycobiology
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• v.51 no.2
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• pp.79-86
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• 2023

In this study, fungal strains designated as KNUF-22-14A and KNUF-22-15A were isolated from soil samples in Korea. These two strains were identified based on cultural and morphological characteristics as well as phylogenetic analyses and were found to be morphologically and phylogenetically identical. Upon their morphological comparison with closely related species, such as Tolypocladium album, T. amazonense, T. endophyticum, T. pustulatum, and T. tropicale, a difference in the size of short phialides [0.6-2.4(-9.3)×0.8-1.4 ㎛] was observed. Meanwhile, these strains had larger conidia (1.2-3.0×1.2-3.0 ㎛) than T. album, T. amazonense, T. endophyticum, and T. tropicale and smaller conidia than T. pustulatum. Phylogenetic analyses using a multi-locus datasets based on ITS, LSU, and SSU showed that KNUF-22-14A and KNUF-22-15A formed a distinct cluster from previously identified Tolypocladium species. Thus, these fungal strains isolated from soil in Korea are proposed as a novel species according to their characteristics and are named Tolypocladium globosum sp. nov.