• Mycobiology
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• 제50권1호
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• pp.55-65
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• 2022

Lichen is a symbiotic mutualism of mycobiont and photobiont that harbors diverse organisms including endolichenic fungi (ELF). Despite the taxonomic and ecological significance of ELF, no comparative investigation of an ELF community involving isolation of a pure culture and high-throughput sequencing has been conducted. Thus, we analyzed the ELF community in Parmotrema tinctorum by culture and metabarcoding. Alpha diversity of the ELF community was notably greater in metabarcoding than in culture-based analysis. Taxonomic proportions of the ELF community estimated by metabarcoding and by culture analyses showed remarkable differences: Sordariomycetes was the most dominant fungal class in culture-based analysis, while Dothideomycetes was the most abundant in metabarcoding analysis. Thirty-seven operational taxonomic units (OTUs) were commonly observed by culture-and metabarcoding-based analyses but relative abundances differed: most of common OTUs were underrepresented in metabarcoding. The ELF community differed in lichen segments and thalli in metabarcoding analysis. Dissimilarity of ELF community intra lichen thallus increased with thallus segment distance; inter-thallus ELF community dissimilarity was significantly greater than intra-thallus ELF community dissimilarity. Finally, we tested how many fungal sequence reads would be needed to ELF diversity with relationship assays between numbers of lichen segments and saturation patterns of OTU richness and sample coverage. At least 6000 sequence reads per lichen thallus were sufficient for prediction of overall ELF community diversity and 50,000 reads per thallus were enough to observe rare taxa of ELF.

• Mycobiology
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• 제50권5호
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• pp.317-325
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• 2022

Endophytic fungi occupy various ecological niches, which reinforces their diversity. As few studies have investigated the endophytic fungi of alpine conifers, we focused on four species of alpine conifers in this study-Abies nephrolepis, Pinus pumila, Taxus cuspidata var. nana, and Thuja koraiensis-and examined them for endophytic fungi. A total of 108 endophytic fungi were isolated. There were four taxa in A. nephrolepis, 12 in P. pumila, 18 in T. cuspidata var. nana, and 17 in T. koraiensis; these were divided into five classes: Agaricomycetes (3.2%), Dothideomycetes (29.0%), Leotiomycetes (15.0%), Sordariomycetes (41.9%), and Orbiliomycetes (1.6%). The most prevalent fungi were Sydowia polyspora (22.7%) and Xylariaceae sp. (22.7%) in P. pumila, Phomopsis juglandina (16.1%) in T. cuspidate var. nana, and Thuja-endophytes sp. 1 (70.0%) in T. koraiensis. However, there was no dominant species growing in A. nephrolepis. Some host plants were analyzed using next-generation sequencing. We obtained 4618 reads for A. nephrolepis and 2268 reads for T. koraiensis. At the genus level, the top three endophytic fungi were Ophiostomataceae_uc (64.6%), Nectriaceae_uc (15.5%), and unclassified organism (18.0%) in A. nephrolepis and Nectriaceae_uc (41.9%), Ophiostomataceae_uc (41.8%), and Magnaporthaceae_uc (9.2%) in T. koraiensis. Our results show that there are different communities of endophytic fungi among different host plants, even if the host plants are in the same region. Such ecological niches are important in terms of the ecological restoration of alpine conifers.

• 한국균학회지
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• 제48권1호
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• pp.39-45
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• 2020

A fungal isolate US-18-11 was isolated from the soil in Uiseong, Korea. The mycelium growth measured after 7 days of incubation at 22℃ on malt extract agar (MEA) and oatmeal agar (OA) media was 42-43 mm and 41-44 mm in diameter, respectively. The fungal colony formed white to dull green aerial mycelia that were floccose with regular margins and olivaceous black with leaden gray patches on the reverse side. The conidia were hyaline to brown in color, ellipsoidal to ovoid, guttulate, abundant, globose, solitary, or confluent measuring 3.2-7.2×1.1-2.3 ㎛. A BLAST search of the large subunit (LSU), internal transcribed spacer (ITS) region, second largest subunit of DNA-directed RNA polymerase II (RPB2) and β-tubulin (TUB2) gene sequences revealed that the isolate US-18-11 has similarities of 99, 100, 97, and 99% with those of Epicoccum draconis CBS 186.83, respectively. A neighbor-joining phylogenetic tree constructed based on the concatenated dataset of above-mentioned sequences showed that isolate US-18-11 clustered with Epicoccum draconis CBS 186.83 in the same clade. Based on the results of morphological, cultural, and phylogenetic analysis, the isolate US-18-11 was identical to the previously described E. draconis CBS 186.83. To our knowledge, this is the first report of E. draconis in Korea.

• Journal of Microbiology and Biotechnology
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• 제30권11호
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• pp.1680-1687
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• 2020

Fungal endophytes are symbiotic microorganisms that are often found in asymptomatic plants. This study describes the genetic diversity of the fungal endophytes isolated from the roots of plants sampled from the west coast of Korea. Five halophytic plant species, Limonium tetragonum, Suaeda australis, Suaeda maritima, Suaeda glauca Bunge, and Phragmites australis, were collected from a salt marsh in Gochang and used to isolate and identify culturable, root-associated endophytic fungi. The fungal internal transcribed spacer (ITS) region ITS1-5.8S-ITS2 was used as the DNA barcode for the classification of these specimens. In total, 156 isolates of the fungal strains were identified and categorized into 23 genera and two phyla (Ascomycota and Basidiomycota), with Dothideomycetes and Sordariomycetes as the predominant classes. The genus Alternaria accounted for the largest number of strains, followed by Cladosporium and Fusarium. The highest diversity index was obtained from the endophytic fungal group associated with the plant P. australis. Waito-C rice seedlings were treated with the fungal culture filtrates to analyze their plant growth-promoting capacity. A bioassay of the Sm-3-7-5 fungal strain isolated from S. maritima confirmed that it had the highest plant growth-promoting capacity. Molecular identification of the Sm-3-7-5 strain revealed that it belongs to Alternaria alternata and is a producer of gibberellins. These findings provided a fundamental basis for understanding the symbiotic interactions between plants and fungi.

• 한국균학회지
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• 제41권3호
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• pp.137-141
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• 2013

오서산의 소나무와 일본잎갈나무 두 수종의 침엽에서 내생균의 다양성을 분석하였다. 총 13개체의 숙수식물에서 채집한 침엽을 표면살균하여 분리한 균주들은 형태적인 특징과 rDNA 유전자(ITS 부위) 분석을 수행하였다. 그 결과 총 37개의 균주가 분리되었으며 이들은 17개의 분류군으로 묶을 수 있었다. 그 중 59%는 Leotiomycetes에 속하였으며, 30%는 Sordariomyetes에, 8%는 Dothideomycetes에 속하였으며, 3%는 Agaricomycetes에 속하는 균으로 판명 되었다. 이러한 결과들은 선행연구의 결과들과 매우 유사하였으며 소나무에서보다 일본잎갈나무에서 내생균의 종 다양성이 높게 나타났다. 특히 Lophodermium 속에 속하는 분류군들이 내생균의 다양성에서 주요한 균류로 확인되었으며, 한국에 분포하는 Lophodermium 속 내 종들에 대한 심도 있는 연구가 요구된다.

• 한국균학회지
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• 제47권1호
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• pp.13-18
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• 2019

A fungal strain, designated PTT-2, was isolated from the bark of the trunk of a persimmon (Diospyros kaki) tree in Cheongdo, Korea. The isolate showed morphological similarities with Leptosphaerulina saccharicola. Strain PTT-2 had more rapid growth on potato dextrose agar medium than on oatmeal agar, malt extract agar, and synthetic nutrient poor agar media, with colony sizes of 53.8 mm, 49.8 mm, 48.4 mm, and 28.1 mm after 7 days at $25^{\circ}C$ temperature, respectively. Strain PTT-2 produced ascospores, which had irregular wavy edges, oblong to ellipsoidal shape, hyaline appearance and $23.6{\times}10{\mu}m$ size. The black ascomata were developed on PDA medium, and asci were recorded. A BLAST search of the internal transcribed spacer (ITS) region, TEF1-${\alpha}$ and RPB2 gene sequences revealed that strain PTT-2 showed more than 99% nucleotide similarity with a strain of Leptosphaerulina saccharicola previously reported from Thailand. A neighbor-joining phylogenetic tree was constructed by concatenating the above-mentioned sequences, and showed that strain PTT-2 clustered in the same clade with L. saccharicola. Based on these findings, this is the first record of Leptosphaerulina saccharicola occurring in Korea.