Neohelicomyces maolanensis J. Ma & Y. Z. Lu, 2025

Peng, Tao, Lu, Yong-Zhong, Bai, Song, Zhang, Jing-Yi, Xiao, Xing-Juan, Wu, Na & Ma, Jian, 2025, Novel Helicosporium and Neohelicomyces (Tubeufiaceae, Tubeufiales) species from terrestrial habitats in China and Thailand, MycoKeys 112, pp. 81-101 : 81-101

Neohelicomyces maolanensis J. Ma & Y. Z. Lu sp. nov.

Fig. 3

Holotype.

HKAS 128855 .

Etymology.

‘‘ maolanensis ’’ refers to its collection site, where the fungus was collected.

Description.

Saprobic on decaying wood in a forest. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on natural substrate superficial, effuse, solitary, scattered or gregarious, white to pale brown. Mycelium partly immersed, partly superficial, composed of pale brown to brown, branched, septate, guttulate, smooth. Conidiophores 201–230 μm long, 3–4.5 μm wide (x ̄ = 220 × 3.5 μm, n = 20), macronematous, mononematous, procumbent, solitary, cylindrical, tapering at tip, flexuous, unbranched, septate, slightly constricted at septa, hyaline to pale brown, smooth-walled, thick-walled. Conidiogenous cells 13.5–18.5 μm long, 2.5–4 μm wide (x ̄ = 16 × 3.5 μm, n = 30), holoblastic, monoblastic to polyblastic, integrated, intercalary or terminal, cylindrical or subcylindrical, with a denticulate protrusion, truncate at apex after conidial secession, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, tapering towards the rounded ends, developing on tooth-like protrusions, 13.5–19 μm diam. and conidial filament 2.5–3 μm wide (x ̄ = 16 × 2.8 μm, n = 30), 105–134 μm long (x ̄ = 116.5 μm, n = 30), aseptate, tightly coiled 3–3 3 / 4 times, becoming loosely coiled when the conidia are young in water and not becoming loose when the conidia mature in water, guttulate, hyaline, smooth-walled.

Culture characteristics.

Conidia germinated on PDA, producing germ tubes within 8 hours. Colonies on PDA reached a diameter of 24 mm after 37 days of incubation at 25 ° C, exhibiting an irregular shape with a flat surface and undulate margin, pale brown to brown in PDA medium.

Material examined.

China • Guizhou Province, Qiannan Buyi and Miao Autonomous Prefecture, Libo County , on rotting wood in a terrestrial habitat, 10 April 2022, Jian Ma, MN 5 ( HKAS 128855 , holotype), ex-type living culture GZCC 23–0079 ; • Ibid., MN 5.1 ( GZAAS 23–0634 , paratype), ex-paratype living culture GZCC 23–0148 .

Notes.

Neohelicomyces maolanensis ( HKAS 128855 ) is morphologically similar to N. deschampsiae ( CBS H–23590 ) in having erect, flexuous, multi-septate, brown conidiophores; monoblastic to polyblastic, intercalary, pale brown conidiogenous cells; and solitary, hyaline conidia ( Crous et al. 2019 a). However, Neohelicomyces maolanensis can be distinguished from N. deschampsiae by its greater number of coils (3–3 3 / 4 times vs. 2–3 times), smaller conidial diameter (13.5–19 μm vs. 19–22 μm), and wider conidial filaments (2.5–3 μm vs. 2–2.5 μm) ( Crous et al. 2019 a). According to the phylogenetic analysis (Fig. 1 ), our new isolates formed a distinct lineage within the clade, which comprises N. helicosporous ( GZCC 23–0633 and GZCC 23–0634 ), N. hyalosporous ( GZCC 16–0086 ), N. qixingyaensis ( CGMCC 3.25569 ), and N. subtropicus ( GZCC 23–0076 and GZCC 24–0147 ), indicating that GZCC 23–0079 and GZCC 23–0148 represent a distinct species. Therefore, we propose Neohelicomyces maolanensis ( GZCC 23–0079 and GZCC 23–0148 ) as a novel species based on molecular and morphological evidence.

Figures

Figure 1. Phylogram generated from the best scoring of the RAxML tree based on the combined LSU, ITS, tef 1 - α, and rpb 2 sequence dataset, indicating Helicosporium and Neohelicomyces species. Botryosphaeria agaves (MFLUCC 10–0051) and B. dothidea (CBS 115476) were selected as outgroup taxa. Bootstrap support values from maximum likelihood (ML) equal to or greater than 75 % and Bayesian posterior probabilities (PP) equal to or greater than 0.95 are shown near the nodes as ML / PP, respectively. “ T ” denotes ex-holotype strains. New species are in bold blue.

Figure 3. Neohelicomyces maolanensis (HKAS 128855, holotype) a colonies on the host surface b – d conidiophores, conidiogenous cells with conidia e, f conidiogenous cells h, i, l – n conidia g germinated conidium j, k surface and reverse colonies on PDA after 37 days of incubation at 25 ° C. Scale bars: 50 μm (b, c); 20 μm (d – f); 10 μm (g); 5 μm (h, i, l – n).