Nigrograna longiorostiolata H. Z. Du & Jian K. Liu 2024, sp. nov.
Creators: name: Du, Hong-Zhi
name: Lu, Yu-Hang
name: Cheewangkoon, Ratchadawan
name: Liu, Jian-Kui
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Fungi
Ascomycota
Dothideomycetes
Pleosporales
Nigrogranaceae
Nigrograna
Nigrograna longiorostiolata

description: Nigrograna longiorostiolata H. Z. Du & Jian K. Liu sp. nov.
Fig. 3
Etymology.
The epithet ‘ longiorostiolata ’ refers to the longer-ostiolate of ascomata.
Holotype.
HKAS 131311
Description.
Saprobic on dead branches of Citrus medica (Rutaceae). Sexual morph: Ascomata 222–293 μm wide, 144–486 μm high (x ̅ = 264 × 303 μm, n = 20), solitary, scattered, immersed, visible as black dots on the host surface, uniloculate, globose to subglobose, sometimes obpyriform with a long ostiole. Ostioles 175–302 μm long, 83–128 μm wide (x ̅ = 263 × 102 μm, n = 20) central or eccentric, longer, with a crest-like apex, filled with hyaline or slightly brown periphyses. Peridium 17–32 μm (x ̅ = 23.5 μm, n = 20) composed of textura prismatica cells, consisting 3–4 layers, brown to dark brown of outer layer, hyaline to subhyaline of inner layer. Hamathecium 1–2 μm (x ̅ = 1.5 μm, n = 20) wide, composed of numerous, filiform, hyaline, aseptate or separate, rarely branched, guttulate, smooth-walled pseudoparaphyses. Asci 40–70 × 6–9 μm (x ̅ = 53 × 8 μm, n = 30), 5–8 - spored, bitunicate, fissitunicate, clavate, short cylindrical pedicellate with a swollen base, apically rounded, with a minute ocular chamber. Ascospores 10–13 × 4–6 μm (x ̅ = 12 × 5 μm, n = 50), 1–2 - seriate, partially overlapping, fusoid to ellipsoid, tapering towards the blunt ends, or blunt at both ends, guttulate, olivaceous to yellowish-brown when young, aseptate or 1 - septate; deeply constricted at septa, becoming 3 - septate, brown to dark brown when mature, without appendages. Asexual morph: Undetermined.
Culture characteristics.
Ascospores germinated on PDA within 24 h, and germ tubes produced from basal cell. Colonies growing on PDA reached 17–18 mm in diameter after three weeks at 25 ° C in dark, white in the whole colony from above, circular, edge entire, margin well-defined; in reverse, off-white to grayish brown, no pigmentation on PDA.
Material examined.
China • Yunnan Province, Xishuangbanna Dai Autonomous Prefecture, Mengla County, Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences. 21°56'1′′N, 101°25'33′′E, elevation 505 m, on dead branches of medicinal plant Citrus medica L. (Rutaceae), 10 November 2022, H. Z. Du, S 655 (HKAS 131311, holotype; HUEST 23.0200, isotype); ex-holotype living culture CGMCC 3.25626; ex-isotype living culture UESTCC 23.0200.
Notes.
Nigrograna longiorostiolata shares similar morphology with N. magnoliae (holotype, MFLU 20–0092) and N. kunmingensis (holotype, ZHKU 22-0141) in having immersed, globose to subglobose ascomata, bitunicate and clavate asci, fusoid to ellipsoid, 3 - septate mature ascospores. However, the ascomata size of N. longiorostiolata (222–293 × 144–486 μm) is larger than N. magnoliae (200–300 × 100–150 μm) (Wanasinghe et al. 2020) and smaller than N. kunmingensis (300–500 × 390–450 µm) (Liu et al. 2024). The phylogenetic result (Fig. 1) showed that N. longiorostiolata (CGMCC 3.25626 and UESTCC 23.0200) can be recognized as a distinct phylogenetic species with high bootstrap support (100 % MLBS / 1.00 BIPP). Additionally, N. longiorostiolata (ex-type strain, CGMCC 3.25626) can be distinguished from N. magnoliae (ex-type strain, MFLUCC 20-0020) by 26 / 471 bp (5.5 %, 2 gaps) in ITS, 14 / 831 bp (1.7 %, without gaps) in LSU, 30 / 855 bp (3.5 %, 3 gaps) in tef 1 - α and 96 / 1042 bp (9.2 %, without gaps) in rpb 2 differences, and differs from N. kunmingensis (ex-type strain, ZHKUCC 22-0242) with 70 / 823 bp (8.5 %, 21 gaps) of ITS, 14 / 844 bp (1.7 %, without gaps) of LSU and 30 / 855 bp (3.5 %, 3 gaps) of tef 1 - α differences. Therefore, N. longiorostiolata associated with Citrus medica is a phylogenetically distinct specie and introduced as a new species.
description: Published as part of Du, Hong-Zhi, Lu, Yu-Hang, Cheewangkoon, Ratchadawan & Liu, Jian-Kui, 2024, Morpho-phylogenetic evidence reveals novel species and new records of Nigrograna (Nigrogranaceae) associated with medicinal plants in Southwestern China, pp. 1-33 in MycoKeys 110 on pages 1-33, DOI: 10.3897/mycokeys.110.132628