Neomonodictys subtropicus W. M. Zhang & L. Lu, 2025

Neomonodictys subtropicus W. M. Zhang & L. Lu sp. nov.

Fig. 2 View Figure 2

Etymology.

The specific epithet “ subtropicus ” refers to the subtropical climate of the collection site.

Holotype.

GZAAS 25-0656

Description.

Saprobic on submerged decaying wood in a freshwater stream. Asexual morph: Conidiomata on natural substratum sporodochial, scattered, gregarious, punctiform, glistening, black. Mycelium mostly superficial, partially immersed, composed of branched, smooth-walled, septate, hyaline to pale brown hyphae. Conidiophores up to 78 μm long, 3.3–4.8 μm wide, macronematous, mononematous, cylindrical, simple, septate, smooth-walled, hyaline. Conidiogenous cell 2.7–5.3 × 3.2–3.8 μm ( x ̄ = 4.5 × 3.5 μm, n = 10), terminal, determinate, integrated, holoblastic, monoblastic, cylindrical, hyaline, sometimes detached with the mature conidia. Conidia 15.5–19 × 8.5–11.5 μm ( x ̄ = 17 × 10.5 μm, n = 60), acrogenous, solitary, oval, obovoid to ellipsoid, aseptate, guttulate, pale brown to dark brown. Sexual morph: Undetermined.

Culture characteristics.

Conidia germinate on PDA within 18 hours, producing germ tubes from the conidial body. Colonies on PDA are circular with a flat surface and entire margin, reaching 2.5 cm in diameter after 29 days at room temperature (approximately 25 ° C), and are grey or pale brown to black on both the surface and reverse sides.

Material examined.

China • Guizhou Province, Zunyi City, Fuxing Town , on rotting wood in a freshwater habitat, 18 April 2025, Wang-Ming Zhang, WW 48 ( GZAAS 25-0656 , holotype), ex-type GZCC 25-0628 ; • Ibid., WW 48.1 ( GZAAS 25-0657 , isotype), ex-isotype GZCC 25-0629 .

Notes.

In the present phylogenetic analysis, Neomonodictys subtropicus ( GZCC 25-0628 and GZCC 25-0629 ) formed a sister lineage to N. muriformis ( MFLUCC 16-1136 ) with 96 % ML and 1.00 BYPP bootstrap support (Fig. 1 View Figure 1 ). Based on the base pair comparison, our isolate ( GZCC 25-0628 , ex-type) differs from N. muriformis ( MFLUCC 16-1136 , ex-type) by 21 / 593 bp for ITS (3.5 %) and 10 / 829 bp (1.2 %) for LSU. Morphologically, Neomonodictys subtropicus ( GZAAS 25-0656 ) can be readily distinguished from N. aquatica and N. muriformis by its cylindrical, hyaline conidiophores, punctiform conidiomata, and aseptate conidia ( Hyde et al. 2020; Huang et al. 2022). Therefore, Neomonodictys subtropicus is introduced here as a new species based on molecular evidence and morphological comparison.