Molecular phylogeny and morphology reveal four new species of Thelephora (Thelephorales, Basidiomycota) from subtropical China, closely related to T. ganbajun

Abstract

The genus of Thelephora is a group of cosmopolitan ectomycorrhizal fungi with basidiocarps of morphological diversity that has an extremely scarce species reported from the forest ecosystem in China. In this study, phylogenetic analyses of Thelephora species from subtropical China were carried out based on multiple loci including the internal transcribed spacer (ITS) regions, the large subunit of nuclear ribosomal RNA gene (nLSU), and the small subunit of mitochondrial rRNA gene (mtSSU). Maximum likelihood and Bayesian analyses were used to construct the phylogenetic tree. The phylogenetic positions of four new species, Th. aquila, Th. glaucoflora, Th. nebula, and Th. pseudoganbajun, were revealed based on morphological and molecular evidence. Molecular analyses demonstrated that the four new species were closely related to Th. ganbajun and formed a clade with robust support in the phylogenetic tree. Regarding morphology, they share some common morphological characteristics, including flabelliform to imbricate pilei, generative hyphae more or less covered by crystals, and subglobose to irregularly lobed basidiospores (5–8 × 4–7 μm) with tuberculate ornamentation. These new species are described and illustrated and are compared to similar morphological or phylogenetically related species. A key to the new and allied species from China is provided.

Ectomycorrhizal fungi inoculation on Shorea balangeran and Tristaniopsis obovata in peatland ecosystems

“…These genera have also been found to form ectomycorrhizal symbiosis with various tree species across the globe. Notable tree families reported to be symbiotic with these two genera include Conifers, Dipterocarpaceae, Fabaceae, and others [21]- [23].…”

Four New Species and One New Record of Thelephora from China

“…These two species share similar sizes of basidiomes (50 × 40 mm in T. aquila vs. 35-65 × 30-40 mm in T. dactyliophora) and similar sizes of basidiospores (5−7.3 × 4−6.5 µm in T. aquila vs. 4.5-7.5 × 4-6.5 µm in T. dactyliophora). However, T. aquila is easily distinguished from T. dactyliophora by its flabelliform to applanate-lobate branches of basidiomes and its black and zonate abhymenial surface which is somewhat radially rugulose or wrinkled [25]. The coralloid basidiomes of T. dactyliophora are very similar to those of T. palmata.…”

“…Microscopic characteristics that include the structure of the pileipellis and the morphology of context hyphae, subhymenium hyphae, basidia, cystidia, and basidiospores were observed under a ZEISS Axiostar Plus microscope (Carl Zeiss AG, Oberkochen, Germany). Tissues were sectioned and mounted in 10% KOH, Cotton Blue (test for cyanophily), and Melzer's reagent (test for amyloidity and dextrinoidity) [13,25,28,29]. Microscopic structures of pileipellis, hymenium, and subhymenium were drawn freehand; basidiospores and hyphae were measured at 1000× g magnification.…”

“…However, T. lacunosa differs from T. sikkimensis clearly in the lacunary, non-zonate, and grayish brown to grayish orange abhymenial surface and the subconical stipe. The yeast powder flavor when drying, the imbricate to rosette basidiomes, and the flabelliform branches of basidiomes make T. ganbajun similar to T. lacunosa, but T. ganbajun has an inconspicuously gray to black abhymenial surface and a brown to yellowish brown stipe which is cylindrical to flatted or broadened [25]. Thelephora lacunosa and T. pseudoganbajun S.R.…”

“…According to our preliminary statistics, 64 species of Thelephora have been accepted (http://www.indexfungorum.org/Names/Names.asp, accessed date: 25 February 2024), and they are mainly distributed in the northern temperate and tropical regions from Europe [15], North America [16][17][18][19][20], and Asia [21,22]. In China, 24 species have been reported [12][13][14][23][24][25]. During our recent research on Thelephora across China, we encountered five impressive species that have not been reported from this country.…”