• The Korean Journal of Mycology
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• v.46 no.4
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• pp.359-367
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• 2018

As an effort to explore fungal diversity, fungal survey was undertaken in 2017 in the vicinity of demilitarized zone (DMZ) located in Yeoncheon-gun, Gyeonggi-do, Korea. For the survey, wild plants and soils were sampled and subjected to fungal isolation. A total of 18 genera and 23 species including five unrecorded fungal species, Mortierella sclerotiella, M. sossauensis, M. verticillate, Eupenicillium saturniforme, and Trichoderma hispanicum, were obtained from the survey. This study described their morphological characteristics including colony features formed on media, light microscopic images and molecular characteristics of nucleotide sequences of the internal transcribed spacer (ITS) region, 18S and 28S rDNA, ${\beta}-tubulin$ gene, calmodulin, and translation elongation factor $1{\alpha}$ ($tef1{\alpha}$) nDNA genes.

• The Korean Journal of Mycology
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• v.50 no.3
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• pp.183-194
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• 2022

Two fungal strains, designated KNUF-21-006 and KNUF-21-028, were isolated from soil samples collected from Gyeongbuk Province, Korea. The strain KNUF-21-006 was similar to other Pestalotiopsis species in terms of morphological characteristics, including whitish to pale brown mycelium, conidial shape, and size. The isolate had aerial hyphae that produced black fruiting bodies on the mycelium. The conidia were fusoid to ellipsoid, four-septate, and appendage-bearing. Phylogenetic analysis using the internal transcribed spacer (ITS) region, translation elongation factor 1-alpha (TEF), and β-tubulin (TUB) gene sequences confirmed that the closest relationship of the isolate at the species level was with Pestalotiopsis clavata. The strain KNUF-21-028 exhibits similar morphological characteristics to other Botryotrichum species, including white aerial mycelium with sulcate and irregular margins, conidial shape, and size. The conidia were globose, single, and hyaline. Upon molecular analysis-using the ITS region, large subunit (LSU) rRNA gene, and TUB gene sequences-the fungus was identified as Botryotrichum iranicum. This is the first record of these fungal species in Korea.

• Research in Plant Disease
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• v.25 no.2
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• pp.94-97
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• 2019

In February 2019, a damping-off disease occurred at the seedling stage of paprika in a commercial nursery located in Cheorwon, Korea. A species of Fusarium was isolated from the diseased plant and it was identified as Fusarium oxysporum based on morphological characteristics and nucleotide sequence data of translation elongation factor $1-{\alpha}$ and the largest subunit of RNA polymerase. The isolate obtained was revealed to be pathogenic to the host plant through pathogenicity tests, and the reisolation of the pathogen confirmed Koch's postulates. This is the first report of damping-off caused by Fusarium oxysporum on paprika in Korea.

• The Korean Journal of Mycology
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• v.47 no.1
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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.

• The Plant Pathology Journal
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• v.28 no.1
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• pp.55-59
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• 2012

Northern stem canker caused by $Diaporthe$ $phaseolorum$ var. $caulivora$ ($Dpc$) has become a serious disease in soybean. The objectives of this study were to survey the existence of $Dpc$ on soybean in Korea, and to examine the potential pathogenicity of $Dpc$ in seed decay. One such isolate, SSLP-4, isolated from a field-grown plant of the Korean soybean cultivar Danbaekkong, was identified as $Dpc$, based on its morphological and molecular characteristics by sequences of internal transcribed spacer (ITS), translation elongation factor (TEF) 1-${\alpha}$ and ${\beta}$-tubulin regions, as well as pathogenic analyses. Moreover, morphological and molecular analyses revealed that isolate SSLP-4 was nearly identical to $Dpc$ strains from the United States. Pathogenicity tests on hypocotyls of soybean seedlings and detached leaves resulted in typical symptoms of soybean northern stem canker and inoculation on plants at R5-R7 stage caused seed decay. All results suggest that the $Dpc$ strain SSLP-4 can cause both stem canker and seed decay on soybean. Thus, the SSLP-4 isolate has the potential to contribute greatly to understanding of host plant resistance mechanisms, both at vegetative and reproductive growth stages in soybean.

• Mycobiology
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• v.43 no.3
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• pp.354-359
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• 2015

Blossom blight in strawberry was first observed in a green house in Nonsan, Damyang, and Geochang areas of Korea, between early January to April of 2012. Disease symptoms started as a grey fungus formed on the stigma, which led to the blossom blight and eventually to black rot and necrosis of the entire flower. We isolated the fungi purely from the infected pistils and maintained them on potato dextrose agar (PDA) slants. To test Koch's postulates, we inoculated the fungi and found that all of the isolates caused disease symptoms in the flower of strawberry cultivars (Seolhyang, Maehyang, and Kumhyang). The isolates on PDA had a velvet-like appearance, and their color ranged between olivaceous-brown and smoky-grey to olive and almost black. The intercalary conidia of the isolates were elliptical to limoniform, with sizes ranging from $5.0{\sim}10.5{\times}2.5{\sim}3.0{\mu}m$ to $4.0{\sim}7.5{\times}2.0{\sim}3.0{\mu}m$, respectively. The secondary ramoconidia of these isolates were 0- or 1-septate, with sizes ranging betweem $10.0{\sim}15.0{\times}2.5{\sim}3.7{\mu}m$ and $8.7{\sim}11.2{\times}2.5{\sim}3.2{\mu}m$, respectively. A combined sequence analysis of the internal transcribed spacer regions, partial actin (ACT), and translation elongation factor 1-alpha (TEF) genes revealed that the strawberry isolates belonged to two groups of authentic strains, Cladosporium cladosporioides and C. tenuissimum. Based on these results, we identified the pathogens causing blossom blight in strawberries in Korea as being C. cladosporioides and C. tenuissimum.

• The Plant Pathology Journal
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• v.32 no.5
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• pp.414-422
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• 2016

Eucalyptus dieback disease, caused by Cylindrocladium scoparium, has occurred in last few years in large Eucalyptus planting areas in China and other countries. Rapid, simple, and reliable diagnostic techniques are desired for the early detection of Eucalyptus dieback of C. scoparium prior to formulation of efficient control plan. For this purpose, three PCR-based methods of nested PCR, multiplex PCR, loop-mediated isothermal amplification (LAMP) were developed for detection of C. scoparium based on factor 1-alpha (tef1) and beta-tubulin gene in this study. All of the three methods showed highly specific to C. scoparium. The sensitivities of the nested PCR and LAMP were much higher than the multiplex PCR. The sensitivity of multiplex PCR was also higher than regular PCR. C. scoparium could be detected within 60 min from infected Eucalyptus plants by LAMP, while at least 2 h was needed by the rest two methods. Using different Eucalyptus tissues as samples for C. scoparium detection, all of the three PCR-based methods showed much better detection results than regular PCR. Base on the results from this study, we concluded that any of the three PCR-based methods could be used as diagnostic technology for the development of efficient strategies of Eucalyptus dieback disease control. Particularly, LAMP was the most practical method in field application because of its one-step and rapid reaction, simple operation, single-tube utilization, and simple visualization of amplification products.

• Mycobiology
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• v.48 no.6
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• pp.450-463
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• 2020

The strains 17E-042, 17E-039, and NC13-171 belong to Ascomycota and were isolated from soil collected from Sancheong-gun and Yeongam-gun, Korea. The strain 17E-042 produced white mycelial colonies that developed a sienna color with a round margin on potato dextrose agar (PDA), and the reverse side developed a light sienna color. Morphologically, this strain was similar to the strains of Arthrinium phragmites and A. hydei, but the shorter conidial size of the newly identified strain (17E-042) was distinct. The strain 17E-039 produced macroconidia that were pale yellow to orange-brown, elongated-ellipsoid to oblong, round at both ends, primarily straight but sometimes slightly curved, 0-septate, thin-walled, and filled with numerous droplets, having diameters of 20.4-34.3 × 8.0-12.0 ㎛. And the strain NC13-171 formed hyaline to light brown chlamydospores, solitary or in a chain. Multigene phylogenetic analyses were conducted using sequence data obtained from internal transcribed spacer (ITS) regions, 28S rDNA large subunit (LSU), β-tubulin (TUB2), translation elongation factor 1-alpha (TEF1-α), and RNA polymerase II large subunit (RPB2) genes. The results of molecular phylogeny, the detailed descriptions and illustrations of each species strongly support our proposal that these strains from soil in Korea be designated as Arthrinium minutisporum sp. nov. and two new records of Pezicula neosporulosa and Acrocalymma pterocarpi.

• Mycobiology
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• v.51 no.2
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• pp.87-93
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• 2023

The fungal strain belonging to the genus Monochaetia of the family Sporocadaceae was isolated from hairy long-horned toad beetle (Moechotypa diphysis) during the screening of microfungi associated with insects from Gangwon Province, Korea. The strain KNUF-6L2F produced white, light brown to dirty black surface, and olivaceous green colonies with the higher growth, while the closest strain M. ilicis KUMCC 15-0520^T were light brown to brown, and M. schimae SAUCC 212201^T light brown to brown toward center. The strain KNUF-6L2F produced shorter (5.7-14.0 ㎛) apical appendages than M. ilicis (6.0-24.0 ㎛), but similar to M. schimae (7.0-12.5 ㎛). Three median cells of KNUF-6L2F were light brown to olivaceous green, whereas brown and olivaceous cells were observed from M. ilicis and M. schimae, respectively. And the strain KNUF-6L2F produced larger conidiogenous cells than M. ilicis and M. schimae. Additionally, phylogenetic analyses based on molecular datasets of internal transcribed spacer (ITS) regions, translation elongation factor 1-alpha (TEF1α), and β-tubulin (TUB2) genes corroborated the strain's originality. Thus, the strain is different from other known Monochaetia species, according to molecular phylogeny and morophology, hence we suggested the new species Monochaetia mediana sp. nov. and provided a descriptive illustration.

• The Plant Pathology Journal
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• v.24 no.4
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• pp.417-422
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• 2008

Apicidin is a cyclic tetrapeptide produced by some Fusarium species and is known to inhibit Apicomplexan histone deacetylase. The goals of this study were to determine species identity of Fusarium isolate KCTC16676, an apicidin producer, to improve a method for apicidin extraction, and to test phytotoxicity of apicidin and its analogs. We compared sequences of the translation elongation factor 1-alpha (TEF) gene in KCTC16676 with those from isolates representing diverse Fusarium species, which showed that KCTC16676 belongs to the F. semitectum-F. equiseti species complex. To enhance apicidin production, after culturing isolate KCTC16676 on a wheat medium for 3 weeks at $25^{\circ}C$, the culture was extracted with chloroform. Apicidins were purified through a reverse phase $C_{18}$ silica gel column, resulting in 5 g of apicidin, 200 mg of apicidin A, and 300 mg of apicidin $D_2$ from 4 kg of wheat cultures; this represents a significant yield improvement from a previous method, offers more materials to study the modes of its action, and facilitates the elucidation of the apicidin biosynthesis pathway. Apicidin and apicidin $D_2$ showed phytotoxicity on both seedlings and 2-week-old plants of diverse species, and weeds were more sensitive to apicidins than vegetables