• 한국균학회지
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• 제47권2호
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• pp.95-104
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• 2019

The genus Ochrolechia is a widespread, lichen genus in Korea. Despite being common, little is known about the species diversity and geographical distribution of Ochrolechia. In this study, we detailed the identification procedure of the genus Ochrolechia in a Korean collection and provided the description of each species. Using 104 specimens collected from 2003 to 2017, we identified four species of the genus Ochrolechia via morphological and/or molecular phylogenetic analysis: O. parellula, O. trochophora, O. yasudae and O. akagiensis. Among them, O. akagiensis had not been previously reported in Korea. Moreover, the species identified as O. frigida and O. tartarea in past studies were corrected as O. yasudae and O. parellula, respectively, based on morphological and/or molecular evidence. Phylogenetic analysis using the internal transcribed spacer regions including 5.8S rRNA gene showed that the four species separated clearly, indicating that the morphological identification corresponds to the phylogenetic identification. We provide a taxonomic key for the four species of the genus Ochrolechia.

• Mycobiology
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• 제49권2호
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• pp.142-150
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• 2021

The species within the family Cunninghamellaceae are widely distributed and produce important metabolites. Morphological studies along with a molecular phylogeny based on the internal transcribed spacer (ITS) and large subunit (LSU) of ribosomal DNA revealed two new species in this family from soils in China, that is, Absidia ovalispora sp. nov. and Cunninghamella globospora sp. nov. The former is phylogenetically closely related to Absidia koreana, but morphologically differs in sporangiospores, sporangia, sporangiophores, columellae, collars, and rhizoids. The latter is phylogenetically closely related to Cunninghamella intermedia, but morphologically differs in sporangiola and colonies. They were described and illustrated.

• Mycobiology
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• 제48권6호
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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.

• 한국균학회지
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• 제48권4호
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• pp.511-518
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• 2020

This study was conducted to isolate and identify the fungal pathogen caused unreported post-harvest disease on apples (cv. Fuji) fruit in Korea. The disease symptoms on apples appeared as irregular, light to dark brown, slightly sunken spots. The three fungal strains were isolated from infected tissues of apple fruits and their cultural and morphological characteristics were completely consistent with those of Plenodomus collinsoniae. The phylogenetic analysis using the internal transcribed spacer (ITS) regions, beta-tubulin (TUB), and the second largest subunit of RNA polymerase II (RPB2) sequences revealed the closest relationship of the isolates with Plenodomus collinsoniae at the species level. The pathogenicity test showed the same dark brown spots on Fuji apple cultivar. Therefore, P. collinsoniae is a newly reported fungal agent causing post-harvest disease on apples in Korea.

• The Plant Pathology Journal
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• 제37권4호
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• pp.329-338
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• 2021

Alternaria leaf blight is one of the most common diseases in watermelon worldwide. In Korea, however, the Alternaria species causing the watermelon leaf blight have not been investigated thoroughly. A total of 16 Alternaria isolates was recovered from diseased watermelon leaves with leaf blight symptoms, which were collected from 14 fields in Korea. Analysis of internal transcribed spacer (ITS) region, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and RNA polymerase II second largest subunit (RPB2) were not competent to differentiate the Alternaria isolates. On the contrary, analysis of amplicon size of the histone H3 (HIS3) gene successfully differentiated the isolates into three Alternaria subgroups, and further sequence analysis of them identified three Alternaria spp. Alternaria tenuissima, A. gaisen, and A. alternata. Representative Alternaria isolates from three species induced dark brown leaf spot lesions on detached watermelon leaves, indicating that A. tenuissima, A. gaisen, and A. alternata are all causal agents of Alternaria leaf blight. Our results indicate that the Alternaria species associated watermelon leaf blight in Korea is more complex than reported previously. This is the first report regarding the population structure of Alternaria species causing watermelon leaf blight in Korea.

• Mycobiology
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• 제49권3호
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• pp.285-293
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• 2021

Polylactic acid (PLA) and polycaprolactone (PCL) are commercially available bioplastics that are exploited worldwide, and both are biodegradable. The PLA and PCL polymer-degrading activity of 30 fungal strains that were isolated from terrestrial environments were screened based on the formation of a clear zone around fungal colonies on agar plates containing emulsified PLA or PCL. Among them, five strains yielded positive results of biodegradation. Strains Korean Agricultural Culture Collection (KACC) 83034BP and KNUF-20-PPH03 exhibited PCL degradation; two other strains, KACC 83035BP and KNUF-20-PDG05, degraded PLA; and the fifth strain, KACC 83036BP, biodegraded both tested plastics. Based on phylogenetic analyses using various combinations of the sequences of internal transcribed spacer (ITS) regions, RPB2, LSU, CAL, and b-TUB genes, the above-mentioned strains were identified as Apiotrichum porosum, Penicillium samsonianum, Talaromyces pinophilus, Purpureocillium lilacinum, and Fusicolla acetilerea, respectively. Based on our knowledge, this is the first report on (i) plastic biodegraders among Apiotrichum and Fusicolla species, (ii) the capability of T. pinophilus to degrade biodegradable plastics, (iii) the biodegradative activity of P. samsonianum against PCL, and (iv) the accurate identification of P. lilacinum as a PLA biodegrader. Further studies should be conducted to determine how the fungal species can be utilized in Korea.

• 한국균학회지
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• 제52권2호
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• pp.97-108
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• 2024

In this study, three fungal isolates belonging to the phylum Ascomycota under classes Leotiomycetes, Eurotiomycetes, and Sordariomycetes were isolated from soil in Korea. These species were designated as KNUF-22-003, KNUF-22-005, and KNUF-20-NI016, respectively, and identified based on their phylogenetic relationships and morphological characteristics. The isolates were confirmed through molecular phylogenetic analyses of their internal transcribed spacer (ITS) region, 28S rDNA large subunit (LSU), and actin (ACT1 ) gene sequences. Cultural and morphological characteristics of strains KNUF-22-003, KNUF-22-005, and KNUF-20-NI016 were matched with Chaetomella oblonga CBS110.78^T, Oidiodendron chlamydosporicum CBS403.69^T, and Sarocladium subulatum CBS217.35^T, respectively. To the best of our knowledge, this is the first report on C. oblonga, O. chlamydosporicum, and S. subulatum in Korea.

• Mycobiology
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• 제38권3호
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• pp.166-170
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• 2010

Gummy stem blight is a major foliar disease of muskmelon (Cucumis melo L.). In this study, morphological characteristics and rDNA internal transcribed spacer (ITS) sequences were analyzed to identify the causal organism of this disease. Morphological examination of the Jeonbuk isolate revealed that the percentage of monoseptal conidia ranged from 0% to 10%, and the average length $\times$ width of the conidia was 70 ($\pm$ 0.96) $\times$ 32.0 ($\pm$ 0.15) ${\mu}m$ on potato dextrose agar. The BLAST analysis showed nucleotide gaps of 1/494, 2/492, and 1/478 with identities of 485/492 (98%), 492/494 (99%), 491/494 (99%), and 476/478 (99%). The similarity in sequence identity between the rDNA ITS region of the Jeonbuk isolate and other Didymella bryoniae from BLAST searches of GenBank was 100% and was 95.0% within the group. Nucleotide sequences of the rDNA ITS region from pure culture ranged from 98.2% to 99.8%. Phylogenetic analysis with related species of D. bryoniae revealed that D. bryoniae is a monophyletic group distinguishable from other Didymella spp., including Ascochyta pinodes, Mycosphaerella pinodes, M. zeae-maydis, D. pinodes, D. applanata, D. exigua, D. rabiei, D. lentis, D. fabae, and D. vitalbina. Phylogenetic analysis, based on rDNA ITS sequence, clearly distinguished D. bryoniae and Didymella spp. from the 10 other species studied. This study identified the Jeonbuk isolate to be D. bryoniae.

• ALGAE
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• 제38권4호
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• pp.241-252
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• 2023

The genera Carolibrandtia and Chlorella have been described as small green algae with spherical cell shapes that inhabit various environments. Species of these genera are often difficult to identify because of their simple morphology and high phenotypic plasticity. We investigated two small coccoid strains from Antarctica based on morphology, molecular phylogeny by two alignment methods which have been applied to previous phylogenetic studies of the genus Chlorella, and comparison of the secondary structures of nuclear small subunit (SSU) and internal transcribed spacer (ITS) rDNA sequences. Light microscopy of two strains revealed spherical cells containing chloroplasts with pyrenoids, and the morphological characteristics of the strains were nearly identical to those of other Chlorella species. However, based on the phylogenetic analyses of nuclear SSU and ITS rDNA sequences, it was determined that the Antarctic microalgal strains belonged to two genera, as the Chlorella and Carolibrandtia. In addition, the secondary structures of the SSU and ITS2 sequences were analyzed to detect compensatory base changes (CBCs) that were used to identify and describe the two strains. A unique CBC in the SSU rDNA gene was decisive for distinguishing strain CCAP 211/45. The ITS2 rDNA sequences for each strain were compared to those obtained previously from other closely related species. Following the comparison of morphological and molecular characteristics, we propose KSF0092 as a new species, Chlorella terrestris sp. nov., and the reassignment of the strain Chlorella antarctica CCAP 211/45 into Carolibrandtia antarctica comb. nov.

• Applied Biological Chemistry
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• 제50권2호
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• pp.101-106
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• 2007

국내 다양한 토양시료로부터 우수 선충포식곰팡이 9 균주를 선발하였다. 순수분리된 선충포식곰팡이는 포식기관의 형태에 따라 3차원적 점착성 그물구조(3-dimensional adhesive nets)를 나타내는 선충포식곰팡이(A 그룹), 2차원적 점착성 그물구조(2-dimensional adhesive nets)를 나타내는 선충포식곰팡이(B 그룹)와 수축성 고리구조(constricting ring)를 나타내는 선충포식곰팡이(C 그룹)로 크게 3개의 형태그룹으로 분류되었다. 이들 각 그룹에 속하는 선충포식곰팡이의 균사체, 분생포자병, 분생포자의 모양과 크기, 분생포자 형성 개수, 분생포자 마디(node), 분생포자 격막의 수와 격막의 위치, 휴면포자의 형성과 크기 및 색 등 형태학적 특징과 선충포식곰팡이의 rDNA ITS 영역을 PCR로 증폭하여 염기서열을 분석한 결과, 분리된 포식곰팡이는 Monacrosporium thaumasium(Kan-2, Kan-4, Kan-11), Arthrobotrys oligospora(Kan-9, Kan-13, Kan-20, Kan-21), A. musiformis (Kan-12), A. dactyloides(Kan-22)로 동정되었다.