Morphological and molecular identification of two new Ganoderma species on Casuarina equisetifolia from China

Abstract

Ganoderma is a cosmopolitan white rot fungal genus, famous for its medicinal properties. In the present study, two new Ganoderma species were collected from south-eastern China and described on the basis of morphological characters and phylogenetic analyses of sequences of the internal transcribed spacer (ITS) region, the translation elongation factor 1-α gene (EF1-α) and the second subunit of RNA polymerase II (RPB2). Specimens of both species were found on living trees of Casuarina equisetifolia. Ganoderma angustisporum sp. nov. is characterised by its sessile basidiomata and almond-shaped, slightly truncate, narrow basidiospores (9–11.3 × 4–5.2 µm). Ganoderma casuarinicola sp. nov. is characterised by its strongly laccate reddish-brown pileal surface, luminous yellow to yellowish-brown cutis and ellipsoid, truncate basidiospores (9–10.2 × 5–6 µm). The two new species are compared with their related taxa. Phylogenetic analyses confirmed that G. angustisporum and G. casuarinicola are distinct species within Ganoderma.

Ganoderma (Ganodermataceae, Basidiomycota) species from the Greater Mekong Subregion

“…Furthermore, there are some similarities between G. tropicum and other Ganoderma 10.4(11.8) × (5.8)6.9-9.3(10.2) μm ( x = 9.4 × 8.8 μm, n = 50), with Q = 1.02-1.14, L = 9.38 µm, W = 8.82 µm (including myxosporium), (6.6)7.9-9.4(10.9) × (5.4)6.3-8.5(9.3) μm ( x = 9.0 × 7.7 μm, n = 50) μm, with Q = 1. (Hapuarachchi et al 2019) and China (Xing et al 2018). The Thai G. orbiforme shares similar features as mentioned by Hapuarachchi et al (2019) and Wang et al (2014), such as possessing an annual to perennial, flabelliform or applanate pileus, with a weakly laccate surface, the presence of several thick layers, an undulate margin, and sub-circular or circular pores.…”

“…casuarinicola from the Guangdong collection does not have the melanoid band (Xing et al 2018), while our collection features a dark brown, melanoid band. Micro-characteristics are dense light-brown to brown context layers; walls of varying thickness in generative hyphae;…”

“…Thailand (Xing et al 2018). Both G. williamsianum strains grouped as sister taxa to the holotype G. mbrekobenum from Ghana (Crous et al 2016) but with low support.…”

“…Cui & Y.C. Dai, Mycokeys 34: 98 (2018) Taxonomy and phylogenic analysis were described in Xing et al (2018) Notes: Ganoderma angustisporum is characterized by annual, sessile, broadly basidiomes, strongly laccate on the upper surface of basidiomes, white pore surfaces, and almond-shaped, slightly truncate, narrow 9.0-11.3 × 4.0-5.2 µm basidiospores. It is a group of white rot fungi which predominantly grows on living Casuarina equisetifolia in Fujian Provinve, China.…”

“…All the other sequences of taxa closely related to our Ganoderma species were retrieved from GenBank. Sequences with high similarity indices were determined from BLAST searches to find the closest matches with taxa and from recently published literatures (Hapuarachchi et al 2018a;Xing et al 2018;Luangharn et al 2019a, b). All sequences used to construct the phylogenetic tree are listed in Table 4.…”