Herpotrichia zingiberacearum Tennakoon & D. M. Hu, 2024

Tennakoon, Danushka S., Thambugala, Kasun M., de Silva, Nimali I., Song, Hai-Yan, Suwannarach, Nakarin, Chen, Fu-Sheng & Hu, Dian-Ming, 2024, An overview of Melanommataceae (Pleosporales, Dothideomycetes): Current insight into the host associations and geographical distribution with some interesting novel additions from plant litter, MycoKeys 106, pp. 43-96 : 43-96

Herpotrichia zingiberacearum Tennakoon & D. M. Hu sp. nov.

Fig. 7

Etymology.

Named after the host family ( Zingiberaceae ) where this fungus was collected.

Holotype.

HFJAU 10332 .

Description.

Saprobic on dead stem of Hedychium coronarium J. Koenig ( Zingiberaceae ). Sexual morph: Ascomata 250–350 × 240–320 µm (x ̄ = 298 × 262 μm, n = 10), solitary to clustered, superficial, dark brown to black, setose, coriaceous, unilocular, globose to subglobose, rounded apex broadly cap-like, ostiolate. Peridium 15–25 μm wide, thick-walled, composed of 4–5 layers of dark brown to black cells, arranged in textura angularis. Hamathecium 1–3 μm wide, comprising dense, filiform, anastomosing, septate, branched pseudoparaphyses, embedded in a gelatinous matrix. Asci 85–98 × 10–14 μm (x ̄ = 94 × 12 μm, n = 20), 8 - spored, bitunicate, fissitunicate, cylindrical clavate, apically rounded, short pedicellate, with an ocular chamber. Ascospores 25–30 × 5–6 μm (x ̄ = 28 × 5.2 μm, n = 30), overlapping, 1–2 - seriate, fusoid with narrowly rounded ends, hyaline, 1 - septate, straight to slightly curved, constricted at the septum, with large guttules, surrounded by an expanded gelatinous sheath pointed at both ends, 2.5–4 μm wide, smooth-walled. Asexual morph: Undetermined.

Material examined.

China, Yunnan Province, Kunming, on a dead stem of Hedychium coronarium ( Zingiberaceae ), 20 July 2016, D. S. Tennakoon, KDS 12 ( HFJAU 10332 , holotype) ; ibid. 21 August 2016, KDS 13 ( HFJAU 10333 , paratype) ; ibid. 25 August 2016, KDS 18 ( HFJAU 10334 , paratype) .

Notes.

Herpotrichia zingiberacearum is isolated from the dead stem of Hedychium coronarium ( Zingiberaceae ). The newly-generated sequences H. zingiberacearum (LSU, SSU, ITS and tef 1 - α) formed a monophyletic clade closely related to H. macrotricha with 90 % ML and 0.99 BYPP statistical support. Morphologically, they share similarities in having dark brown to black, setose, coriaceous ascomata, cylindrical clavate asci and hyaline, 1 - septate ascospores ( Mugambi and Huhndorf 2009). However, H. zingiberacearum can be distinguished from H. macrotricha in their smaller asci (85–98 × 10–14 μm vs. 115–145 × 11–13 μm) and ascospores (25–30 × 5–6 μm vs. 30–35 × 4–6 μm) ( Tanaka and Hosoya 2006). On the other hand, H. zingiberacearum ( HFJAU 10332 ) differs from H. macrotricha ( GKM 196 N) by a comparison of the 694 nucleotides across the tef 1 - α gene region which shows 20 base pair differences (3.02 %). This finding addresses future studies to explore the diversity of Herpotrichia species in different geographic regions and host plants, as these species have not previously been described from Zingiberaceae hosts (Table 2 ).

Figures

Figure 7. Herpotrichia zingiberacearum (HFJAU 10332, holotype) a, b appearance of ascomata on the host c vertical section of an ascoma d peridium e pseudoparaphyses f – h asci i – l ascospores m ascospore stained in Indian ink showing a mucilaginous sheath. Scale bars: 100 µm (c); 20 µm (d); 50 µm (e – h); 15 µm (i – m).