The aim of this study was to characterize a new fungal species, Acremonium conglutinatum, isolated from air samples collected in Wando, South Korea. Phylogenetic analysis based on the internal transcribed spacer and large subunit regions revealed its unique position within the genus Acremonium. The isolated strain displayed distinct morphological characteristics, including ellipsoid or bent-ellipsoid conidia formed in clusters on the phialides. These features differentiate the new species from closely related species within the genus. This study describes the morphological and molecular characteristics of A. conglutinatum and emphasizes its phylogenetic relationships with other Acremonium spp. The identification of this novel species contributes to our understanding of the diversity and ecological role of Acremonium.

This study examined the effects of myristate on an asymbiotic culture of Rhizoglomus intraradices, a species of arbuscular mycorrhizal fungi (AMF; Glomeromycota). Mycelial growth and sporulation in a modified medium containing myristate were observed. The findings demonstrated that myristate induced R. intraradices spore formation, with daughter spores having a smaller diameter than the parent spores. This observation is consistent with previous studies on other Rhizoglomus species. Further studies are needed to investigate the potential for continuous culture, mass production using daughter spores, and the application of AMF colonization techniques in plants.

Fungi of the genus Tuber are ectomycorrhizal fungi that form a symbiotic relationship mainly with oak and hazel trees. Tuber spp. exhibit a highly selective host plant preference; thus, for cultivation purposes it is important to select an appropriate host plant for successful mycorrhization. In addition, as mycorrhizal characteristics differ according to Tuber spp., it is necessary to understand the differences in mycorrhizae according to the fungal species. Tuber huidongense and Tuber himalayense were recently discovered in Korea; therefore, we used spore suspensions from these two species to inoculate two species of oak trees, Quercus acutissima and Quercus dentata, to compare colonization rates and morphologies of the mycorrhizae. The colonization rates demonstrated that the different Tuber spp. favored different host plant species. In addition, unique morphological and anatomical characteristics were observed for T. huidongense and T. himalayense depending on the host species. These findings can lead to new economically important agricultural activities related to truffle cultivation in Korea.

Members of the genus Tuber are ectomycorrhizal fungi; this genus includes more than 180 species worldwide. In the present study, the optimal pH, temperature, and medium suitable for the mycelial growth of the Korean truffle, Tuber koreanum, were determined. Mycelium of T. koreanum, isolated from fruiting bodies collected in Korea, was used to investigate the effects of these environmental factors. The results showed that malt extract agar and potato dextrose agar were the most suitable for the mycelial growth of T. koreanum when cultured at a pH of 6.0 at 25 C for 30 days.

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. cuspidata 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. nephrolepisand 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.

The truffle and ectomycorrhizal roots formed by Tuber sp. were collected from the rhizosphere of Quercus aliena in Korea. The morphological characteristics of the ascoma, and molecular phylogenetic analysis using sequences from the internal transcribed spacer (ITS) and large subunit (LSU) of ribosomal DNA, translation elongation factor 1-alpha (TEF), and RNA polymerase second largest subunit (RPB2) regions confirmed the distinct morphology of the truffle. This truffle belongs to a monophyletic clade among the other Tuber species in the phylogeny. This study describes the truffle, Tuber koreanum, as a new species reported from Korea.

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 μm. 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.

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 μm. 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.

A new species of arbuscular mycorrhizal fungi (Glomeromycota), Acaulospora koreana, was isolated from forest soils in South Korea. This novel fungus was collected from the rhizosphere of Lindera obtusiloba and Styrax obassia in forest and propagated with Sorghum bicolor in pot. Morphological characteristics of spores of A. koreana are rarely distinguished from Acaulospora mellea, which is reported as one of the most abundant mycorrhizal species in Korea. However, molecular evidence of rDNA sequence using improved primers for glomeromycotan fungal identification strongly supported that A. koreana is different from A. mellea but also any other species belonging to the genus Acaulospora. This is the first novel glomeromycatan fungus introduced in South Korea, but it suggests that there is a high possibility for discovering new arbuscular mycorrhizal fungi considering the abundance of plant species and advanced phylogenetic analysis technique.
DNA, Ribosomal ; Forests ; Fungi* ; Glomeromycota ; Korea* ; Lindera ; Plants ; Rhizosphere ; Soil ; Sorghum ; Spores ; Styrax

Orchidaceous plants have symbiotic relationships with endophytic fungi, including mycorrhizal fungi, which play important roles in the seed germination and growth of the host plants. In this study, endophytic fungal communities isolated from the roots of Cephalanthera longibracteata collected from three different sites in Korea were analyzed, and it was determined whether fungal communities were preferentially correlated with the sites. The fungal isolates were identified by sequence analysis of the internal transcribed spacer regions of rDNA. In total, 30 species of endophytic fungi, including two species of mycorrhizal fungi belonging to the genus Tulasnella, were identified. Leptodontidium orchidicola showed the highest frequency and was isolated from all root samples. Species diversity and richness were not significantly different among sites. However, the community structure of the endophytic fungi significantly differed among sites, suggesting that the site characteristics affected the community composition of the endophytic fungi colonizing the roots of C. longibracteata. Our findings will aid in developing methods involving the use of symbiotic fungi for orchid conservation and restoration in native habitats.
Colon ; DNA, Ribosomal ; Ecosystem ; Fungi ; Germination ; Korea* ; Mycorrhizae ; Sequence Analysis