Neocosmospora bostrycoides (Wollenw. & Reinking) Sandoval-Denis, L. Lombard and Crous, Persoonia 43: 115 (2019)

Fig. 9

Description.

Associated with contaminated rubber latex. Sexual morph: Undetermined. Asexual morph on PDA: Conidiophores abundant on aerial and substrate mycelium, erect and simple, straight or flexuous, smooth- and thin-walled, bearing terminal or lateral, forming monophialides on the apices. Phialides (11 –) 15 × 30 (– 35) × 2.5–5 μm (x – = 22 × 4 μm, n = 30), subcylindrical to subulate, monophialidic, smooth- and thin-walled with a short flared apical collarette. Aerial conidia 5–11 × 2.5–5 μm (x – = 6.8 × 3.6 μm, n = 50), obovoidal, broadly ellipsoidal to ellipsoidal, straight or rarely curved, 0 (– 1) - septate, hyaline, smooth- and thin-walled, clustering abundantly in false heads at the tip of monophialides. Sporodochial conidiophores sparingly verticillately branched, bearing terminal whorls of 2–3 - monophialides. Sporodochial phialides 11–20 × 3–4 μm (x – = 15 × 3.4 μm, n = 30), flask-shaped, subcylindrical to short subulate, smooth- and thin-walled, conidiogenous loci with inconspicuous periclinal thickening and collarette. Sporodochial conidia 22–38 × 4–6 μm (x – = 31 × 4.6 μm, n = 50), moderately to distinctly dorsiventrally curved narrowing gently toward base, dorsal line usually almost straight; apical cell often equal in length to adjacent cell, blunt and rounded with curved apex; basal cell often distinctly notched, 1–4 - septate, hyaline, smooth- and thick-walled. Chlamydospores 6–10 μm diam., abundantly formed, globose to subglobose, smooth- and thick-walled, terminal or intercalary in hyphae or conidia, solitary, in chains or in clusters.

Culture characteristics.

Colonies on PDA at room temperature (20–25 ° C) covered the entire 6 cm Petri dish within three days, white to pale yellow, with abundant aerial mycelium; reverse white to pale yellow. Sporulation was observed after prolonged incubation on PDA at room temperature.

Material examined.

China, • Yunnan Province, Lincang City, contaminated rubber latex, 28 July 2022, Rui-Fang Xu, L-12 A (GMB-W 1263), living culture GMBCC 2519.

Notes.

Phylogenetic analysis placed strain GMBCC 2519 within the Neocosmospora bostrycoides lineage, supported by 100 % ML and 1.00 BYPP values (Fig. 6). Morphologically, GMB-W 1263 closely resembles the reference strain Neocosmospora bostrycoides (CBS 130391). It aligns with the species description but is characterized by shorter sporodochial conidia (22–38 μm vs. 40.5–51.5 μm) (Sandoval-Denis et al. 2019). Nucleotide comparisons revealed differences of 5 bp in ITS (2 gaps), 3 bp in LSU (0 gaps), and 6 bp in rpb 2 (0 gaps) between GMBCC 2519 and Neocosmospora bostrycoides (CBS 144.25). Neocosmospora bostrycoides was collected from contaminated old rubber latex in a container near a rubber tree. In the present study, this species showed measurable surface-associated changes on natural rubber under laboratory incubation conditions.