Re‐evaluation of Armillaria and Desarmillaria in South Korea based on ITS/tef1 sequences and morphological characteristics

Abstract

Fungal species in the genera Armillaria and Desarmillaria (Physalacriaceae, Agaricales) are well known for their symbiotic relationships with Gastrodia elata and Polyporus umbellatus, important components of traditional medicine in Asia. In addition, some species in these genera cause Armillaria root disease, which has had a negative economic impact by damaging and destroying urban, horticultural and forest trees. Five species within Armillaria and Desarmillaria have been previously reported in South Korea, based primarily on basidioma morphology: A. cepistipes, A. gallica, A. mellea, A. ostoyae and D. tabescens (reported as A. tabescens). This study re‐evaluated 60 specimens of Armillaria and Desarmillaria using morphological features and molecular phylogenetic analyses of the ITS and partial translation elongation factor‐1α (tef1) sequences. In addition, spatial distributions of each Armillaria and Desarmillaria species in South Korea were determined from combined data based on basidioma collections and environmental DNA (eDNA). Six species (A. cepestipes, A. gallica, A. mellea, A. nabsnona, A. ostoyae and D. tabescens) and three lineages of A. gallica (A. gallica clade 1–3) were identified in South Korea from both specimens and eDNA. Most of the basidioma specimens used in this study were previously identified as A. mellea; however, in this study, no basidioma specimens were identified as A. mellea, although this species was detected on Jeju Island from eDNA samples. The detection of A. nabsnona was a new report for South Korea. Consistent with previous phylogenetic studies, the tef1 analysis had better resolution than the ITS analysis. These distribution data of Armillaria and Desarmillaria species will contribute to better management of Armillaria root disease as well as cultivation of G. elata and P. umbellatus in South Korea.

Armillaria Root-Rot Pathogens: Species Boundaries and Global Distribution

“…Within this group, A. ostoyae , A. borealis and A. gemina , are morphologically similar in having a thick anulus, stipes that are more or less equal in shape and the presence of distinct dark scales [55]. Armillaria ostoyae (proposed by [56] as A. solidipes because this is the older name, but not always accepted [57]) has a transcontinental distribution, occurring in Europe, North America and Asia (China, Japan and South Korea), A. borealis occurs in both Europe and Asia (China) while A. gemina is confined to north-eastern North America [31,58,59,60] and as shown in Figure 2 (Table S4).…”

“…Armillaria ectypa occurs as a saprophyte on woody material found in peat bogs and marshy habitats (e.g., [54]). Armillaria tabescens has a much broader distribution than A. ectypa being reported from southern Europe [52,58], North and Central America [89,90,91], South Korea [60,92,93], southern Japan [71] and China [59,94]. In some of these regions they are considered important pathogens on woody shrubs and trees (e.g., [91]).…”

Taxonomic Study of the Genus Pholiota (Strophariaceae, Basidiomycota) in Korea

“…As such, it is important to proceed with further identification using molecular analysis, which has become an increasingly important tool for accurately identifying fungal species [11,12]. We recently discovered many new fungal species and amended misidentified species by reevaluating the other genera using molecular analysis [13][14][15][16][17][18][19].…”

The complete mitochondrial genome of the edible and phytopathogenic fungus Desarmillaria tabescens

“…Under natural conditions, this mushroom causes armillaria root rot (Amiri et al 2008;Baumgartner et al 2018) and participates in a symbiotic relationship with Galeola septentrionalis (Terashita and Chyuman 1987). Studies related to D. tabescens had been primarily limited to its phylogenetic relationships and distribution (Hasegawa et al 2011;Coetzee et al 2015;Park et al 2017) and phytopathology (Amiri et al 2008;Baumgartner et al 2018). This study is the first to report the complete mitogenome sequence of D. tabescens (GenBank accession no.…”

“…Studies related to D . tabescens had been primarily limited to its phylogenetic relationships and distribution (Hasegawa et al 2011 ; Coetzee et al 2015 ; Park et al 2017 ) and phytopathology (Amiri et al 2008 ; Baumgartner et al 2018 ). This study is the first to report the complete mitogenome sequence of D .…”