• The Korean Journal of Mycology
• /
• v.49 no.2
• /
• pp.183-197
• /
• 2021

Various freshwater ecosystems, such as streams, lakes and rivers, provide a dynamic habitat for fungi. In this study, we isolated several fungal strains from freshwater sediment and plant litter. The strains were identified using molecular phylogenetic analyses of rDNA and beta tubulin (TUB) sequences. Morphological characteristics of the fungi were also investigated using microscopy and culture characteristics of the fungi grown on several media. We identified seven species previously unrecorded in Korea, Nothophoma spiraeae, Westerdykella aquatica, W. aurantiaca, W. dispersa, Chrysosporium sanyaense, C.pseudomerdarium and Taeniolella phialosperma.

• Mycobiology
• /
• v.49 no.3
• /
• pp.267-274
• /
• 2021

Two Diaporthe species isolated from fruit of Citrus sinensis in China were characterized based on morphology and multilocus phylogeny of ITS, tef1, and tub2 gene sequences. The phylogeny indicated that the two species match Diaporthe taoicola and D. siamensis. A critical examination of phenotypic characteristics confirmed the phylogenetic results. Diaporthe taoicola was morphologically characterized by producing Alpha conidia with tapering toward both ends. Meanwhile, D. siamensis produced cylindrical or ellipsoidal Alpha conidia with two oil drops. Pathogenicity tests revealed that both species were pathogenic to fruit of C. sinensis. To our knowledge, the two species were firstly reported on Citrus sinensis in China.

• The Korean Journal of Mycology
• /
• v.49 no.3
• /
• pp.417-423
• /
• 2021

Apple decline symptoms were frequently observed on cv. Fuji apple orchards located in Gyeonggi, Gyeongbuk, and Gangwon provinces during surveys conducted from May until the end of September 2020. Three fungal strains were isolated from the margins of internal lesions of diseased apple trees, and their morphological characteristics were considered similar to Botryosphaeria sinensis. Phylogenetic analysis using internal transcribed spacer (ITS) regions, translation elongation factor 1-alpha (tef1), beta-tubulin (tub2), and the second largest subunit of RNA polymerase II (rpb2) gene sequences confirmed the closest relationship of isolates with B. sinensis at the species level. According to a pathogenicity test, the appearance of dark-brown discolorations and vascular necrosis on apple branches inoculated with the isolated strain KNUF-20-014 was observed. To the best of our knowledge, this is the first report of B. sinensis as the causal agent of apple disease in Korea.

• Mycobiology
• /
• v.49 no.1
• /
• pp.54-60
• /
• 2021

During the screening of Korean microflora, a fungal strain (KNU-PT-1804) belonging to the genus Pestalotiopsis was isolated from persimmon tree (Diospyros kaki) bark collected from North Gyeongsang Province, Korea. The strain, KNU-PT-1804, produced smaller conidia compared with related species P. kenyana, P. neglecta, and P. telopeae. The novelty of the strain was confirmed based on phylogenetic analysis using molecular datasets of internal transcribed spacer (ITS) regions, β-tubulin (TUB2), and translation elongation factor 1-alpha (TEF1α) genes. Molecular phylogeny strongly supports that the strain is distinct from previously known Pestalotiopsis species, and we proposed the novel species, Pestalotiopsis kaki sp. nov., and provide a detailed description and illustration.

• Mycobiology
• /
• v.50 no.2
• /
• pp.99-103
• /
• 2022

A new fungus isolated from the leaves of Eleutharrhena macrocarpa in southern Yunnan, China is described using morphological and molecular evidence. Phylogenetic trees based on the combined nuclear ribosomal DNA internal transcribed spacer (ITS), translation elongation factor-1α (TEF1), and β-tubulin gene (TUB2) sequences showed that Diaporthe eleutharrhenae sp. nov. is sister to Diaporthe chinensis N.I. de Silva, Lumyong & K.D. Hyde and morphologically differs in shorter alpha conidia (5-8.5× 1.5-2 ㎛) and the presence of beta conidia. This study also resolves a nomenclatural problem, as two taxa were published using the same name. To avoid confusion, the unrelated D. chinensis H. Dong, J. W. Xia & X. G. Zhang is here renamed as D. dongii (H. Dong, J. W. Xia & X. G. Zhang) S. J. Song & Landrein, sp. nov. in honor of the author that described this species. Study and description of fungi associated with threatened tropical species could help to understand their ecology as well as the potential spread of fungi onto cultivated crop species.

• The Korean Journal of Mycology
• /
• v.50 no.1
• /
• pp.1-29
• /
• 2022

Hypocreales is one of the largest orders within the class Sordariomycetes in Ascomycota. Several species of this order are cosmopolitan and have a broad range of habitats. Here, we isolated several fungal strains from environmental samples, including freshwater sediment and plant litter. The strains were identified via molecular and phylogenetic analyses of rDNA and other DNA markers, such as TUB, RPB2, and EF1. The morphological characteristics of the fungi were investigated using microscopy, and culture characteristics were assessed from their growth on several media. We identified 17 species previously unrecorded in Korea: Dactylonectria hordeicola, Flavocillium bifurcatum, Fusarium luffae, Ilyonectria ilicicola, Ilyonectria qitaiheensis, Ilyonectria robusta, Lecanicillium aphanocladii, Nectria ulmicola, Neonectria lugdunensis, Ovicillium oosporum, Pseudonectria foliicola, Sarocladium spinificis, Scolecofusarium ciliatum, Trichoderma appalachiense, Trichoderma subviride, Trichoderma taiwanense, and Trichoderma tsugarense.

• Mycobiology
• /
• v.51 no.6
• /
• pp.393-400
• /
• 2023

During a disease survey in October 2019, leaf spot symptoms with a yellow halo were observed on Korean angelica (Anglica gigas) plants grown in fields in Pyeongchang, Gangwon Province, Korea. Incidence of diseased leaves of the plants in the investigated fields ranged from 10% to 60%. Morphological and cultural characteristics of two single-spore isolates from the leaf lesions indicated that they belonged to the genus Didymella. Molecular phylogenetic analyses using combined sequences of LSU, ITS, TUB2, and RPB2 regions showed distinct clustering of the isolates from other Didymella species. In addition, the morphological and cultural characteristics of the isolates were somewhat different from those of closely related Didymella spp. Therefore, the novelty of the isolates was proved based on the investigations. Pathogenicity of the novel Didymella species isolates was confirmed on leaves of Korean angelica plants via artificial inoculation. This study reveals that Didymella gigantis sp. nov. causes leaf spot in Korean angelica.

• Mycobiology
• /
• v.51 no.5
• /
• pp.313-319
• /
• 2023

During disease surveys of Angelica acutiloba plants in Korea, leaf spot symptoms were observed in a field in Andong in July 2019, and stem rot symptoms in vinyl greenhouses in Yangpyeong in April 2020. Incidence of leaf spot and stem rot of the plants ranged from 10 to 20% and 5 to 30%, respectively. Morphological and cultural characteristics of fungal isolates from the leaf spot and stem rot symptoms fitted into those of the genus Phoma. Molecular phylogenetic analyses of two single-spore isolates from the symptoms using concatenated sequences of LSU, ITS, TUB2, and RPB2 genes authenticated an independent cluster from other Didymella (anamorph: Phoma) species. Moreover, the isolates showed different morphological and cultural characteristics in comparison to closely related Didymella species. These discoveries confirmed the novelty of the isolates. Pathogenicity of the novel Didymella species isolates was substantiated on leaves and stems of A. acutiloba through artificial inoculation. Thus, this study reveals that Didymella acutilobae sp. nov. causes leaf spot and stem rot in Angelica acutiloba.

• The Korean Journal of Mycology
• /
• v.51 no.4
• /
• pp.441-446
• /
• 2023

Bamboo is host to diverse range of fungi, however, research on bambusicolous fungi remains insignificant in Korea. The genus Apiospora is prevalent in various environments, particularly as endophytic fungi in Poaceae, to which bamboo belongs. In this study, endophytic fungi were isolated from stems of Pseudosasa japonica collected from Gongjusi, Korea. To identify these endophytic fungi, we observed morphological characteristics and conducted phylogenetic analysis using internal transcribed spacer (ITS), large subunit ribosomal DNA (LSU), and β-tubulin (TUB2) DNA, identifying and describing an unrecorded fungus, Apiospora pseudosinensis.

• The Plant Pathology Journal
• /
• v.40 no.4
• /
• pp.399-407
• /
• 2024

Dieback disease in mango trees has been observed in Indonesia, particularly in Java Island, with the causal agent remaining unidentified. One of the important pathogens that are responsible for causing mango dieback is Colletotrichum. Field surveys were conducted in various mango cultivating areas in Java Island, Indonesia to assess prevalence of Colletotrichum as dieback disease pathogen. Eleven Colletotrichum isolates were recovered from symptomatic dieback twigs and morphologically characterized. Genetic diversity fingerprint analysis was carried out using rep-PCR. Phylogenetic analysis identified isolates as belonging to Colletotrichum asianum and Colletotrichum cairnsense using partial sequences of four gene regions, including ITS, ACT, GAPDH, and TUB2. Pathogenicity tests on mango seedlings cv. Arumanis showed that all fungal isolates were responsible for causing dieback symptoms. Subsequently, symptomatic tissue was reisolated to fulfill Koch's Postulate. This study represented new funding for two species of Colletotrichum causing mango dieback in Indonesia.