Pleurostoma richardsiae (Nannfeldt) Réblová & Jaklitsch

Yang, Erfu, Karunarathna, Samantha C., Shao, Shicheng, Han, Lisu, Samarakoon, Milan C., Elgorban, Abdallah M., Chiu, Chuni, Tibpromma, Saowaluck & Promputtha, Itthayakorn, 2025, Additions to Termitomyces aurantiacus growing termite comb-associated fungi, Phytotaxa 690 (2), pp. 212-230 : 222

Pleurostoma richardsiae (Nannfeldt) Réblová & Jaklitsch , PLoS ONE 10 (12): e0144616, 30(2015)

Index Fungorum number: IF814423

Harboured in termite fungus gardens. Colonies on PDA low convex, white to brown. Hyphae 1.5–4.5 μm (x = 2.7 μm, n = 20), branched, tubular, septate, thick-walled, hyaline to brown, of uneven thickness.Asexual morph: Conidiophores 8–14 × 2–4 μm (x = 11 × 2.5 μm, n = 20), developed on aerial or submerged hyphae, erect, unbranched, cylindrical, septate, straight or bent, transparent to brown. Conidiogenous cells phialidic, discrete, ampulliform, with a narrow collarette at the tip. Conidia 4–6.5 × 2–3 μm (x = 5.5 × 2 μm, n = 20) hyaline, globose to ovate when mature, mostly straight, aseptate, smooth-walled with oil droplets. Sexual morph: Undetermined.

Substrata: Wood decay of almond trees ( Olmo et al. 2015); grapevine trunk disease ( Rolshausen et al. 2010, Carlucci et al. 2015, Pintos Varela et al. 2016); grapevine decline diseases of grapevine ( Ozben et al. 2017); dieback of olive trees ( Calvo-Peña et al. 2022); termite fungus garden (this study).

Distribution: The USA ( Rolshausen et al. 2010); Italy ( Carlucci et al. 2015); Spain ( Olmo et al. 2015, Pintos Varela et al. 2016, Calvo-Peña et al. 2022); Türkiye ( Ozben et al. 2017); and China (this study).

Culture characteristics: Colonies grow moderately on PDA, reaching approximately 30 mm in diameter after one month. Obverse: circular, raised, white at the center, brown outwardly, entire edge; reverse: browner from center to margin. No pigments are produced on the PDA.

Material examined: China, Yunnan Province, Xishuangbanna Tropical Botanical Garden, on active termite fungus gardens, 20 July 2022, E.F. Yang, W1 ( HKAS 129052), living culture KUNCC 22-12519. GenBank numbers, ITS: PP915826, LSU: PP911541, SSU: PP911544, tub2: PP918925.

Notes: The ITS, LSU, and tub2 genes of our isolate were searched using BLASTn and shared 99–100% similarity with Pleurostoma richardsiae strains ( CBS 406.93, CBS 483.80 and NCPF 7565), and the multi-gene phylogram also shown our isolate ( KUNCC 22-12519) clusters closely with other Pleurostoma richardsiae strains (100 in ML; 1 in BI; Figure 7 ). Therefore, here we report the asexual morph of Pleurostoma richardsiae associated with termite fungus gardens for the first time ( Figure 8 ).

Figures

FIGURE 7. Phylogram of Pleurostoma constructed using maximum likelihood analysis, based on a combined LSU, SSU, ITS, and tub2 sequence dataset. The analysis encompassed 28 strains and a total of 1605 characters (LSU: 1–565 bp, SSU: 566–1593 bp, ITS: 1594–2174 bp, tub2: 2175–2647 bp). Newly introduced species are highlighted in red, and the type strains are indicated in bold. Bootstrap values equal to or higher than 60% (ML, left) and Bayesian posterior probabilities equal to or higher than 0.95 (BI, right) are indicated at the nodes, while hyphens (-) denote values below these thresholds for ML/BI.

FIGURE 8. Pleurostoma richardsiae (HKAS129052): (a) Colony on PDA, (b) Mycelium, (c,d) Conidiophore bearing conidiogenous cells and conidia, (e) Conidia.