Fomitiporia tasmanica G.M. Gates, X.H. Ji & Jia J Chen, 2021

Chen, Jia-Jia, Wu, Ying-Da, Ji, Xiao-Hong, Gates, Genevieve & Xu, Xiang, 2021, A new species of Fomitiporia (Hymenochaetales) from Australia, Phytotaxa 489 (2), pp. 200-208 : 202-206

Fomitiporia tasmanica G.M. Gates, X.H. Ji & Jia J Chen , sp. nov. ( Figs. 3 , 4 )

MycoBank no.: MB 835633

Diagnosis:—Differs from other Fomitiporia species by the combination of a perennial, resupinate basidiocarp, very small pores (10–12 per mm), presence of hymenial setae and cystidioles, and subglobose basidiospores measuring 5.5–6.6 × 5–6 µm.

Type:— AUSTRALIA. Tasmania: Arve River Streamside Reserve, on fallen trunk of Nothofagus , 15 May 2018, Dai 18793 (Holotype in BJFC! isotype in MEL) .

Etymology:— tasmanica (Lat.) : referring to the distribution of the species in Tasmania, Australia.

Fruiting body:—Basidiocarp perennial, resupinate, inseparable, without odour or taste when fresh; woody hard in consistency, light in weight when dry, extending up to 30 cm long, 9 cm wide, up 20 mm thick at centre; margin yellowish brown when dry; up to 2 mm wide. Pore surface clay pink to clay buff and uncracked when fresh, clay buff and uncracked up on drying, distinctly shining; pores circular to angular, 10–12 per mm; dissepiments thin and entire. Subiculum rust brown, up to 5 mm thick. Tubes concolorous with pore surface when dry, distinctly stratified, up to 15 mm long.

Hyphal structure:—Hyphal system dimitic; generative hyphae simple septate; all hyphae IKI–, CB–; tissue darkening but otherwise unchanged in KOH.

Context:—Generative hyphae hyaline to pale yellow, thin- to slightly thick-walled, occasionally branched, frequently septate, 3–4 µm in diam; skeletal hyphae yellowish brown, dominant, sometimes branched, 3–5 µm in diam.

Tubes:—Tramal generative hyphae hyaline to pale yellowish, thin- to slightly thick-walled, occasionally branched, frequently simple septate, 2.5–3.5 µm in diam; skeletal hyphae dominant, yellowish brown, thick-walled with a wide lumen, unbranched, straight, parallel along the tubes, 3–4 µm in diam.

Hymenium:—Hymenial setae present, ventricose, dark brown, 16–24 × 5–7.5 μm; cystidioles present, fusoid, hyaline, thin-walled, 9–17 × 3–5 μm; basidia clavate, with four sterigmata and a simple septum at the base, 12–16 × 7–10 µm; basidioles dominant in hymenium, in shape similar to basidia, but slightly smaller; big rhomboid crystals present among hymenium; basidiospores subglobose to globose, hyaline, thick-walled, smooth, dextrinoid in Melzer’s reagent, CB+, (5.2–)5.5–6.5(–7) × 5–6(–6.5) µm, L = 6.0 µm, W = 5.6 µm, Q = 1.06–1.08 (n=60/2).

Type of rot:—White rot.

Additional specimen (paratype) examined: AUSTRALIA. Tasmania: Arve River Streamside Reserve , on base of living tree of Atherosperma , 15 May 2018, Dai 18799 ( BJFC & MEL) .

Fomitiporia tasmanica has a typical morphology of Fomitiporia , such as subglobose to globose, hyaline, thickwalled, strongly dextrinoid and cyanophilous basidiospores. However, it can be distinguished from existing Fomitiporia species with a resupinate habit by the combination of very small pores (10–12 per mm), presence of hymenial setae and cystidioles, and subglobose basidiospores measuring 5.5–6.6 × 5–6 µm.

In our phylogeny ( Fig. 1–2 ), F. tasmanica is closely related to F. australiensis . However, F. australiensis has resupinate to pileate basidiocarps, larger pores (3–5 per mm), lacks of hymenial setae, and has larger ellipsoid basidiospores measuring 6–8 × 5–6.5 µm ( Fischer et al. 2005). F. punctata which was originally described from Europe is a cosmopolitan species ( Decock et al. 2007, Dai 2010, Ryvarden & Melo 2017) and was also reported from Tasmania. However, the Tasmanian specimens of F. punctata can be distinguished from F. tasmanica by their effusedreflexed basidiocarps and nondextrinoid and acyanophilous basidiospores ( Cunningham 1965).

Macroscopically, F. tasmanica is similar to F. tenuis Decock, Bitew & G. Castillo (2015:122) , both species sharing the resupinate, effused basidiomata, the presence of hymenial setae, cystidioles, and small pores (10–12 per mm). Fomitiporia tenuis differs in having a dimitic hyphal structure throughout the basidiocarp, and growing from living liana in Africa ( Decock et al. 2005). Moreover, the two species are genetically distant and belong to different lineages ( Fig. 1 ).

Fomitiporia tasmanica is related to F. calkinsii (Murrill) Vlasák & Kout (2011: 449 ; Fig. 1–2 ) and both species have comparable basidiospores size (5–6.5 × 5–6 µm in F. calkinsii ). Fomitiporia . calkinsii has pileate basidiocarps, larger pores (6–8 per mm), no setae and it occurs in southeastern USA ( Vlasák & Kout 2011).

Fomitiporia bannaensis Y.C. Dai (2001: 17) , is similar to F. tasmanica by sharing perennial basidiocarps and the presence of hymenial setae; but the former species has bigger pores (8–10 per mm), smaller basidiospores (4.2–5.2 × 3.8–4.8 µm), and occurs in tropical forests of China ( Dai et al. 2001). In the phylogeny, F. bannaensis and F. tasmanica also occupied separate lineages ( Fig. 1 ).

Esca disease associated with white rot has been found to be caused by various species within the order Hymenochaetales , such as Fomitiporia australiensis , F. punctata , F. capensis M. Fisch., Cloete, L. Mostert & Halleen (2014: 307) , and F. mediterranea M. Fisch. (2002: 321) . Two specimens of F. tasmanica from Australia were collected from fallen trunk of Nothofagus and living tree of Atherosperma , respectively. So far, F. tasmanica has not been observed to lead to Esca disease. Therefore, we are not sure if the new species could cause Esca disease. Further studies are in progress to clarify the accurate pathogenicity of F. tasmanica on grapevines.

Figures

FIGURE 1. Phylogeny of Fomitiporia inferred from the ITS and 28S dataset.Topology is from MP tree and statistical values (ML/MP/BI) are indicated for each node that simultaneously received BS from ML and MP not below 50%, and BPP from BI not below 0.90. Branch lengths reflect expected changes per site as indicated by the scale.

FIGURE 2. Phylogeny of Fomitiporia tasmanica and its related species inferred from the ITS dataset. Topology is from MP tree and statistical values (ML/MP/BI) are indicated for each node that simultaneously received BS from ML and MP not below 50%, and BPP from BI not below 0.90. Branch lengths reflect expected changes per site as indicated by the scale.

FIGURE 3. Basidiocarps of F. tasmanica (Holotype). Scale bar = 1 cm.

FIGURE 4. Microscopic structures of Fomitiporia tasmanica (Holotype). a: Basidiospores. b: Basidia and basidioles. c: Cystidioles. d: Setae. e: Trama hyphae. f: Subiculum hyphae.