Taxonomic Revision of the Genus Lactifluus (Russulales, Basidiomycota) of South Korea

Lactifluus(Pers.) Roussel is an ectomycorrhizal genus that was recently recognized to be distinct from the genus Lactarius. To date, 226 Lactifluus species have been reported worldwide. Misidentification of Lactifluus species is common because of intraspecific morphological variation, cryptic diversity, and the limited number of taxonomic keys available. Molecular data are indispensable for species delimitation; a multilocus phylogenetic analysis showed that most Asian Lactifluus species are not conspecific with morphologically similar species present on other continents. In particular, Korea has misused European and North American Lactifluus names. In this study, we evaluated the taxonomy of Lactifluus in Korea using both morphological and multilocus molecular (ITS, nrLSU, rpb1, and rpb2) data.We examined 199 Lactifluus specimens collected between 1980 and 2016, and a total of 24 species across the four Lactifluus subgenera were identified. All Korean species are distinct and clearly separated from European and North American species. Five taxa corresponded to previously described species from Asia and the remaining 19 taxa are confirmed as new species. Herein, we provide keys to the Korean Lactifluus species within their subgenera, molecular phylogenies, a summary of diversity, and detailed description of the new species.

Taxonomic Revision of the Genus Lactifluus (Russulales, Basidiomycota) of South Korea

Lactifluus(Pers.) Roussel is an ectomycorrhizal genus that was recently recognized to be distinct from the genus Lactarius. To date, 226 Lactifluus species have been reported worldwide. Misidentification of Lactifluus species is common because of intraspecific morphological variation, cryptic diversity, and the limited number of taxonomic keys available. Molecular data are indispensable for species delimitation; a multilocus phylogenetic analysis showed that most Asian Lactifluus species are not conspecific with morphologically similar species present on other continents. In particular, Korea has misused European and North American Lactifluus names. In this study, we evaluated the taxonomy of Lactifluus in Korea using both morphological and multilocus molecular (ITS, nrLSU, rpb1, and rpb2) data.We examined 199 Lactifluus specimens collected between 1980 and 2016, and a total of 24 species across the four Lactifluus subgenera were identified. All Korean species are distinct and clearly separated from European and North American species. Five taxa corresponded to previously described species from Asia and the remaining 19 taxa are confirmed as new species. Herein, we provide keys to the Korean Lactifluus species within their subgenera, molecular phylogenies, a summary of diversity, and detailed description of the new species.

Macrolepiota in Korea: New Records and a New Species

The genus Macrolepiota (Agaricales, Basidiomycota) is easy to recognize at the genus level because of big, fleshy basidiocarps with squamules covering the pileus; a single or double annulus; and big, thick-walled basidiospores with a germ pore. However, morphological identification is often unreliable in Macrolepiota due to similar morphological features among species. Due to the uncertainty of previous morphological identification in the genus Macrolepiota, it is necessary to re-examine Korean Macrolepiota using molecular data. We re-examined 34 Macrolepiota specimens collected from 2012 to 2018 in Korea using a reverse taxonomic approach, whereby species identification was first done based on the internal transcribed spacer (ITS) region analysis, followed by morphological confirmation. We identified the presence of four species: M. detersa, M. mastoidea, M. procera, and M. umbonata sp. nov. Two species (M. detersa and M. mastoidea) were previously unrecorded from Korea and M. umbonata is a new species. Detailed descriptions of all four species and taxonomic key are provided in this study. Macrolepiota procera and M. umbonata are distributed through the country, but M. detersa and M. mastoidea are distributed only in limited areas. According to our results, the combination of ITS locus and morphology proved to be a robust approach to evaluate the taxonomic status of Macrolepiota species in Korea. Additional surveys are needed to verify the species diversity and clarify their geographic distribution.

Taxonomic Study of the Genus Abundisporus in Korea

The polypore genus Abundisporus Ryvarden is characterized by resupinate to pileate fruitbodies with a purplish brown hymenophore, slightly thick-walled, pale yellowish and non-dextrinoid basidiospores, and causing white rot. A purple color hymenophore, an easily observable and striking character, was considered the main distinctive feature at the generic level within polypores. However, due to highly similar basidiocarp features, species identification within these purple polypores is particularly difficult. Three species of purple colored polypores have been reported in Korea (Abundisporus fuscopurpureus, A. pubertatis, and Fomitopsis rosea). Based on morphological re-examination, ecological information, and sequence analysis of the internal transcribed spacer, we showed that previous classification was incorrect and there is only one species (A. pubertatis) in Korea. We provide a detailed description of A. pubertatis in Korea, as well as a taxonomic key to distinguish wood rot fungi with a purple hymenophore.

Four New Species of Amanita in Inje County, Korea

Amanita (Agaricales, Basidiomycota) is one of the most well-known genera composed of poisonous mushrooms. This genus of almost 500 species is distributed worldwide. Approximately 240 macrofungi were collected through an ongoing survey of indigenous fungi of Mt. Jeombong in Inje County, Korea in 2014. Among these specimens, 25 were identified as members of Amanita using macroscopic features. Specimens were identified to the species level by microscopic features and molecular sequence analyses of the internal transcribed spacer and large subunit of nuclear ribosomal RNA. We molecularly identified 13 Amanita species, with seven species matching previously recorded species, four species (A. caesareoides, A. griseoturcosa, A. imazekii, and A. sepiacea) new to Korea, and two unknown species.

Molecular Taxonomical Re-classification of the Genus Suillus Micheli ex S. F. Gray in South Korea

The fungal genus Suillus Micheli ex S. F. Gray plays important roles in the survival and growth of plant seedlings. Humans have utilized these ectomycorrhizal fungi to enhance the nutrient uptake and defense systems of plants, particularly in the reforestation of coniferous forests. The genus Suillus is easily distinguishable by its distinctive morphological features, although the morphology of the fruiting body does not facilitate reliable interspecies discrimination. On the basis of micro-morphological features and internal transcribed spacer sequence analysis, we found that 51 of 117 Korean Suillus specimens had initially been misidentified. The list of the 12 Suillus species previously recorded in Korea was re-evaluated and revised to only eight distinct species: S. americanus, S. bovinus, S. granulatus, S. grevillei, S. luteus, S. pictus, S. placidus, and S. viscidus. We provide taxonomical descriptions for six of these species from the sample specimens.

A New Record of Penicillium antarcticum from Marine Environments in Korea

During a survey of marine fungi from the waters surrounding Jeju Island, Korea, several Penicillium strains were isolated from seawater and marine sponges. Based on morphological characteristics and phylogenetic analyses of the internal transcribed spacer and RNA polymerase subunit II, four strains were identified as Penicillium antarcticum, a fungus that, to the best of our knowledge, had not been previously reported in Korea. Here, we provide detailed descriptions of the morphological characteristics and extracellular enzyme activities of the four strains.

A Checklist of the Basidiomycetous Macrofungi and a Record of Five New Species from Mt. Oseo in Korea

Basidiomycetous macrofungi play important roles in maintaining forest ecosystems via carbon cycling and the mobilization of nitrogen and phosphorus. To understand the impact of human activity on macrofungi, an ongoing project at the Korea National Arboretum is focused on surveying the macrofungi in unexploited areas. Mt. Oseo was targeted in this survey because the number of visitors to this destination has been steadily increasing, and management and conservation plans for this destination are urgently required. Through 5 field surveys of Mt. Oseo from April to October 2012, 116 specimens of basidiomycetous macrofungi were collected and classified. The specimens were identified to the species level by analyzing their morphological characteristics and their DNA sequence data. A total of 80 species belonging to 57 genera and 25 families were identified. To the best of our knowledge, this is the first study to identify five of these species-Artomyces microsporus, Hymenopellis raphanipes, Pholiota abietis, Phylloporus brunneiceps, and Sirobasidium magnum-in Korea.

Delimitation of Russula Subgenus Amoenula in Korea Using Three Molecular Markers

Distinguishing individual Russula species has been difficult due to extensive phenotypic plasticity and obscure morphological and anatomical discontinuities. Due to highly similar macroscopic features, such as the presence of a red-cap, species identification within the Russula subgenus Amoenula is particularly difficult. Three species of the subgenus Amoneula have been reported in Korea. We used a combination of morphology and three molecular markers, the internal transcribed spacer (ITS), 28S nuclear ribosomal large subunit (LSU), and RNA polymerase II gene (RPB2), for identification and study of the genetic diversity of Russula subgenus Amoenula in Korea. We identified only two species in Korea (R. mariae and R. violeipes); these two species were indistinguishable according to morphology and LSU, but were found to be reciprocally monophyletic species using ITS and RPB2. The markers, ITS, LSU, and RPB2, have been tested in the past for use as DNA barcoding markers, and findings of our study suggest that ITS and RPB2 had the best performance for the Russula subgenus Amoneula.