Neodeightonia guineensis Y.R. Xiong, Manawas. & K.D. Hyde, 2025

Xiong, Yinru, Manawasinghe, Ishara S., Lu, Li, Mapook, Ausana, Alotibi, Fatimah & Hyde, Kevin D., 2025, Neodeightonia guineensis sp. nov., a palmicolus species from Guangdong, China, Phytotaxa 681 (1), pp. 81-92 : 85

Neodeightonia guineensis Y.R. Xiong, Manawas. & K.D. Hyde , sp. nov. ( Fig. 2 )

Index Fungorum number: IF903050, Facesoffungi number: FoF 16988

Etymology:— Epithet refers to the host species from which the fungus was isolated.

Holotype:— MHKU 24-0149

Saprobic on petiole of Elaeis guineensis ( Arecaceae ). Sexual morph: Ascomata 150–180 × 210–290 µm (x = 160 × 240 µm; n = 10), semi-immersed, solitary, gregarious, unilocular, raising host surface and producing papillate black dots of dehiscence. Peridium 15–55 μm wide (x = 30 µm; n = 20), thick-walled, brown-black cells of textura angularis, smooth, asci developing amongst partially disintegrating sterile thin-walled tissue in locule. Hamathecium 3–6.5 μm wide (x = 4.5 µm, n = 30), pseudoparaphyses, gelatinized, pluricellular, hyaline, constricted at the septa. Asci 80–165 × 20–35 µm (x = 110 × 30 µm; n = 20), bitunicate with a thick endotunica, fissitunicate, separated from one another by stromatic tissue, clavate, 8-spored, with a minute club pedicel. Ascospores 28–32 × 13–15 µm (x = 30 × 14 µm; n = 30), biseriate, hyaline to pale brown, ellipsoidal, muriform when mature, aseptate, rough, surrounded by a tightly fitting mucilaginous sheath. Asexual morph: not observed.

Culture characters:— colonies on PDA reaching 7 cm diam., at 28 ˚ C after five days. Upper view wrinkled, filamentous, entire margin, flat, cloudy, fluffy for aerial hyphae, becoming grey-black with age, dense aerial hyphae, reverse becoming black.

Material examined:— CHINA. Yunnan Province: Xishuangbanna City, in an unidentified forest beside National Highway 219 (21°93'N, 101°24E, 549.6 m), on rotting petiole of Elaeis guineensis , 5 February 2023, Y. R. Xiong and Li Lu, XG 180 ( MHZU 24-0149 , holotype) ; ex-type, ZHKUCC 24-0105 , other living culture ZHKUCC 24-0106 .

Notes:— Two isolates from this study formed a well-separated lineage with 93% ML, 99% MP and 0.99 BIPP support within Neodeightonia species, clustering with N. palmicola . The nucleotide differences excluding gaps of ITS between N. guineensis ( ZHKUCC 24-0105) and N. palmicola ( MFLUCC 10-0822) is 3.65% (19/521 base pairs). Neodeightonia guineensis is a sexual morph and differs from N. palmicola , which has slightly larger asci (154.2 × 20.5 µm) and smaller ascospores (27 × 10 µm) ( Liu et al. 2010). In addition, N. palmicola has ascospores with bipolar germ pores ( Liu et al. 2010), whereas they are absent in N. guineensis . Moreover, N. palmicola has ascospores surrounded by a thick complex sheath ( Liu et al. 2010), while N. guineensis is surrounded by a thin, tightly fitting mucilaginous sheath. Based on the phylogenetic placement and morphological variations, we introduce N. guineensis as a novel Neodeightonia species.

Figures

FIGURE 2. Neodeightonia guineensis (MHZU 24-0149 holotype). a–b. Ascomata on decaying Elaeis guineensis. c. Section of ascoma. d. Peridium. e. Hamathecium. f–i. Asci. j–p. Ascospores (p stained in India ink). q. Germinating conidium. r, s. Top (r) and reverse (s) of culture on PDA at 25 ℃. Scale bars: c = 40 µm, d–i = 20 µm, j–p = 10 µm, q = 50 µm.