Dothiorella saprophytica, Farias & Louangphan & Afshari, 2023

Farias, Antonio Roberto Gomes De, Louangphan, Johnny & Afshari, Naghmeh, 2023, Dothiorella saprophytica sp. nov.: a new Dothiorella sexual morph from Thailand, Phytotaxa 616 (2), pp. 149-159 : 152-154

Dothiorella saprophytica sp. nov. N. Afshari, Gomes de Farias A.R., & J. Louangphan FIGURE 1 .

Index Fungorum number: IF901064, Facesoffungi number: FoF14840

Etymology —Concerning the saprobic life mode of the fungus.

Holotype —MFLU 23-0359

Saprobic on woody litter. Sexual morph: Ascomata 250–450 × 220–350 μm (x̄ = 350 × 293 μm, n = 5), pseudothecial, immersed, moderately erumpent in the bark at maturity, dark brown to black, globose to subglobose or irregular in shape, ostiole papillate, central, circular. Peridium 25–53 μm wide (x̄ = 40 μm, n = 30), composed of textura angularis pseudoparenchymatous cells, outer layer dark brown thick-walled, inner layer subhyaline to hyaline, thinner-walled cells. Hamathecium composed of 2.5–5.3 μm wide (x̄ = 4 μm, n = 30) pseudoparaphyses, hyaline, thin-walled, unbranched, septate, slightly constricted at the septum. Asci 140.5– 168(–196) × 20.5–25 μm (x̄ = 153 × 23 μm, n = 10), basal, stipitate, clavate, bitunicate, well-developed apex-bearing chamber, rounded at apex, 6–8-spored, irregularly biseriate. Ascospores 20–34 × 9–13.5 μm (x̄ = 26 × 11 μm, n = 30), oblong, ovoid to sub-clavate, 0–1-septate (septate at maturity), widest in the center, slightly constricted at the septum, dark brown at maturity, partly thick-walled, finely verruculose on the inner surface, smooth surface, straight, cells obtuse or acute towards ends. Asexual morph: Not observed.

Culture characteristics: Ascospores germinated on PDA within 24 hours, and the germ tube was produced from both end cells. Colonies on PDA reaching up to 9 cm diam. at 25 °C, circular to slightly irregular and raised, thinner towards the edge, margin diffuse, at first pale olivaceous in the center and white towards margin, later becoming dark greenish olivaceous, from above, reverse olivaceous to black.

Material examined: THAILAND, Chiang Mai Province, Mushroom Research Center (MRC), MaeTaeng District, Pha Deng Village . On an unidentified decaying wood, November 2022, J. Louangphan, MC07 ( MFLU 23- 0359 , holotype), ex-type living culture MFLUCC 23-0210 .

GenBank accession numbers: ITS: OR527239; tef1-α: OR532455; β-tub: OR532454.

Notes: Dothiorella saprophytica isolated from dead branches (MFLUCC 23-xxx) was found to be a distinct lineage in the phylogenetic trees of each locus (ITS, tef1 -α, and β-tub) and the combined gene dataset (ITS+ tef1-α + β-tub). It is sister to D. chiangmaiensis , with 1.0 PP and 100% ultrafast bootstrap support ( Fig. 1 ). Dothiorella chiangmaiensis was isolated from dead branches of Tamarindus indica in Thailand ( Rathnayaka et al. 2022). Morphologically, D. saprophytica has bitunicate asci with 6–8 spores and ovoid to sub-clavate, 0–1-septate ascospores that are dark brown at maturity. Pairwise base comparison between D. saprophytica and D. chiangmaiensis revealed 98.95% identity (473/478, 2 gaps) for the ITS and 96.60% identity (227/235, 6 gaps) for the tef1-α. The β-tub was not compared as it is not available for D. chiangmaiensis . Based on the polyphasic approach for fungal taxonomy ( Chethana et al. 2021; Maharachchikumbura et al. 2021), which includes phylogenetic analysis and genetic differences, D. saprophytica is introduced as a new species.

Figures

FIGURE 1. A phylogram of the Dothiorella species based on the multilocus (ITS, tef1-α, and β-tub) sequence alignment, Neofusicoccum luteum (CMW 41365 and CBS 562.92) and Lasiodiplodia americana (CFCC 50065) as outgroup. Bayesian posterior probabilities and Maximum likelihood ultrafast bootstraps and ≥ 0.95 and ≥ 70%, respectively, are shown at the nodes. Ex-type cultures are marked in bold. The strain obtained in the present study is in blue. The scale bar indicates the predicted substitution rate per site.