Parafuscosporella lignicola L. Li & R.J. Xu, 2023

Li, Lu, Xu, Rong-Ju, Luo, Zong-Long, Zhao, Qi & Cheewangkoon, Ratchadawan, 2023, Parafuscosporella lignicola sp. nov. (Fuscosporellaceae), from a freshwater habitat in northern Thailand, Phytotaxa 597 (2), pp. 141-152 : 145-148

Parafuscosporella lignicola L. Li & R.J. Xu , sp. nov. FIGURE 3

Index Fungorum number: IF559931, Facesoffungi number: FoF 12889

Etymology: Referring to the fungus dwelling on wood.

Holotype: MFLU22-0101

Saprobic on decaying twigs from freshwater habitats. Asexual morph: Colonies on natural substratum sporodochial, scattered, black without covering. Mycelium mostly superficial, partially immersed, composed of branched, smooth-walled, septate, hyaline to light brown hyphae. Conidiophores micronematous, mononematous, compact, septate, mostly subglobose to ellipsoidal in moniliform. Conidiogenous cells 11–19 × 7–9 μm (x = 14× 8 μm, n =20), holoblastic, monoblastic, integrated or discrete, terminal, ellipsoidal or cylindrical, hyaline, smooth-walled, sometimes with continuous proliferations. Conidia 15–25 × 8–13 μm (x = 22 × 11 μm, n =40) acrogenous, solitary, ellipsoidal, obovoid or pyriform, with a septum near the base, olivaceous when young, dark brown to black when mature, pale brown at basal cell, truncate at base, smooth-walled.

Sexual morph: Undetermined.

Culture characteristics: Conidia germinating on PDA within 48h. Germ tubes produced from the basal cell. Colonies reaching 30 mm at room temperature in dark for one month, on PDA medium, flat, velutinous, light grey from the center then becoming brown towards surface, sparse mycelium on the surface, irregular margin. Sporulated conidia in cultures after 10 days. Conidiophores micronematous, branched, sometimes reduced to a single conidiogenous cell, hyaline to pale brown. Conidiogenous cells monoblastic, holoblastic, integrated, cylindrical, hyaline to pale brown, smooth-walled. Conidia 10–25 × 8–14 μm (x = 17 × 11 μm, n=20), acrogenous or pleurogenous, globose to subglobose, olivaceous when young, medium brown to dark brown when mature, sometime with continuous proliferations ( FIGURE. 4 ).

Known distribution: Thailand

Material examined: Thailand, Nang Lae, Mueang Chiang Rai, Chiang Rai Province , (99°52′52.93″E, 20°3′2.52″N), saprobic on decaying wood submerged in a freshwater stream, 18 July 2020, R.J Xu, MD-5 ( MFLU22- 0101 holotype), ex-living culture MFLUCC 23-0047 . Thailand, Mushroom Research Center (M.R.C.), Chiang Mai Province, (98°46′44.28″E, 19°7′7.62N ″), unidentified decaying wood in freshwater habitat, 13 July 2020, R.J Xu, MD-5-3 ( MFLU22-0102 ), living culture MFLUCC 23-0048 .

Notes: Morphologically, Parafuscosporella lignicola is similar to P. aquatica , P. moniliformis , P. mucosa , P. nilotica , P. obovate and P. pyriformis in having micronematous, mononematous conidiophores; monoblastic, integrated, globose, subglobose, ellipsoidal conidiogenous cells; subglobose, ellipsoidal or pyriform, dark brown to black conidia. However, P. lignicola has moniliform, ellipsoidal conidiophores, ellipsoidal or cylindrical conidiogenous cells and the smallest conidia in the genus ( Boonyuen et al. 2016, Yang et al. 2016, 2017, Boonmee et al. 2021).

Phylogenetic analysis also shows that Parafuscosporella lignicola has its own distinct lineage compared to other species of Parafuscosporella and form a sister group with P. ellipsoconidiogena ( FIGURE 2 ). However, P. ellipsoconidiogena can be distinguished from P. lignicola by having doliiform, fusiform conidiophores, fusiform conidiogenous cells and larger conidia (27.5–33 × 15–20 μm vs. 15–25 × 8–13 μm) ( Boonyuen et al. 2021).

Figures

FIGURE 2. The results of the pairwise homoplasy index (PHI) test for Parafuscosporella lignicola and closely related species using LogDet transformation. PHI test results (Φw) <0.05 indicate significant recombination within the dataset.

FIGURE 3. Parafuscosporella lignicola (MFLU22-0101 holotype). a Specimen b, c Colonies on substrate. d, e Conidiophores with conidia. f–i Conidiogenous cells and conidia. j Conidia. Scale bars: d = 10μm, e = 20μm, f–j = 10 μm.

FIGURE 4. Sporulation of Parafuscosporella lignicola (XXX ex-type) on PDA. a Germinated conidium on PDA. b Obverse (left) and reverse (right) views of a colony on PDA. c–g Hyphae, conidiophores, conidia and conidiogenous cells from culture. Scale bars: a, c = 20 μm, d = 50 μm, e–g =20μm.