Montagnula coffeae L. Lu & Tibpromma, 2025

Lu, Li, Karunarathna, Samantha C., Rajeshkumar, Kunhiraman C., Elgorban, Abdallah M., Jayawardena, Ruvishika S., Hongsanan, Sinang, Suwannarach, Nakarin, Kumla, Jaturong, Xiong, Yin-Ru, Hyde, Kevin D., Han, Mei-Yan, Zheng, De-Ge, Li, Qiang, Dai, Dong-Qin & Tibpromma, Saowaluck, 2025, Unveiling fungal diversity associated with coffee trees in China using a polyphasic approach and a global review of coffee saprobic fungi, IMA Fungus 16, pp. e 144874-e 144874 : e144874-

Montagnula coffeae L. Lu & Tibpromma sp. nov.

Fig. 4

Etymology.

The species epithet “ coffeae ” refers to the host plant genus “ Coffea ” from which the fungus was isolated.

Diagnosis.

Differs from M. appendiculata (Aptroot) Wanas., E. B. G. Jones & K. D. Hyde , by 6–8 - spored asci, differing from M. chromolaenae Mapook & K. D. Hyde , by guttulate ascospores and differing from M. chiangraiensis Mapook & K. D. Hyde , by the presence of appendages on its ascospores.

Holotype.

HKAS 137611 .

Description.

Saprobic on decaying branch of C. arabica . Teleomorph: Ascomata 120–180 µm high × 150–220 µm diam. (x- = 150 × 183 µm, n = 15), immersed, separate beneath a clypeus or sometimes gregarious beneath fused clypei, visible as black, solitary or scattered, globose to subglobose, unilocular, black, with ostioles. Ostioles papillate, central. Clypeus brown or sometimes with a halo around the central pore, margin indistinct, consisting of dark, thick-walled hyphae in both epidermal and subepidermal cells. Peridium 7–11 µm wide (x- = 8.8 µm, n = 15), fused with host tissue, comprising 2–3 layers of pale brown to brown cells of textura prismatica. Hamathecium 3–6 µm wide (x- = 4 µm, n = 20) µm wide, branched, hyaline, septate, numerous pseudoparaphyses. Asci 60–75 × 6–10 µm (x- = 65 × 8.5 µm, n = 20), bitunicate, fissitunicate, 6–8 - spored, clavate, long-stalked with club-shape, straight. Ascospores 12–16 × 3–6 µm (x- = 14 × 4.8 µm, n = 30), hyaline to yellowish when immature, brown to red-brown when mature, overlapping uniseriate or biseriate, fusiform to ellipsoid, 1 - septate, guttulate, constricted at the septum, upper cell wider and shorter than lower cell and tapering towards ends, sheath drawn out to form polar appendages 4–9 µm long × 1.5–2.5 µm wide (x- = 6 × 1.9 µm, n = 30), from both ends of the ascospores, straight. Anamorph: Not observed.

Culture characteristics.

Ascospores germinating on PDA within 24 h, colonies reached 3.5–4 cm in diameter after one month at 25 ° C. Colonies on PDA irregular, flat or slightly raised, filamentous, smooth, with undulate margin, from above, hyaline, from below, yellowish at the centre, hyaline at the edge.

Materials examined.

China • Yunnan Province, Lincang , on a decaying branch of Coffea arabica ( Rubiaceae ) (24°17'N, 99°99'E, 960 m alt.), 28 July 2022, LiLu, LC 1 - C 5 ( HKAS 137611 , holotype), isotype MHZU 23-0060 , ex-type living culture KUNCC 24-18337 = KUNCC 24-18338 , ex-isotype living culture ZHKUCC 23-0630 = ZHKUCC 23-0631 .

Notes.

In the concatenated phylogenetic analysis, Montagnula coffeae forms a distinct lineage and is basal to M. appendiculata , M. chromolaenae and M. chiangraiensis (Fig. 5 ). Based on nucleotide comparisons, M. coffeae ( ZHKUCC 23-0630 ) differs from M. appendiculata ( CBS 109027 ) by 30 / 497 bp (6 %, without gaps) in ITS and 14 / 833 bp (1.7 %, without gaps) in LSU; differs from M. chromolaenae ( MFLUCC 17-1435 ) by 24 / 497 bp (4.8 %, without gaps) in ITS, 12 / 903 bp (1.3 %, without gaps) in LSU and 15 / 1006 bp (1.5 %, without gaps) in SSU; differs from M. chiangraiensis ( MFLUCC 17-1420 ) by 20 / 498 bp (4 %, without gaps) in ITS, 13 / 903 bp (1.4 %, without gaps) in LSU and 10 / 1006 bp (1 %, without gaps) in SSU. The morphology of M. coffeae is similar to M. appendiculata and M. chromolaenae in having fusiform, brown and fusiform ascospores with appendages. However, M. coffeae has 6–8 - spored asci, while M. appendiculata has 8 - spored asci (Fig. 4 ; Aptroot (2004)). Montagnula coffeae have guttulate ascospores, while no guttules have been observed on the ascospores of M. chromolaenae ( Mapook et al. 2020) . Montagnula coffeae can be distinguished from M. chiangraiensis by the appendages on its ascospores ( Mapook et al. 2020). In addition, the PHI test results (Fig. 22 b ) revealed no significant recombination relationships between M. coffeae and its phylogenetically related taxa. The morphological differences and phylogenetic analysis results support the discovery of M. coffeae as a new species.

Figures

Figure 4. Montagnula coffeae (HKAS 137611, holotype). A, B ascomata on a decaying branch of C. arabica; C longitudinal section of an ascoma; D peridium wall; E pseudoparaphyses; F – J immature and mature asci; K germinated ascospore; L – Q ascospores; R culture on PDA from obverse and reverse. Scale bars: 50 μm (C); 20 μm (D – K); 10 μm (L – Q).

Figure 5. Phylogram generated from the best scoring RAxML tree, based on a combined ITS, LSU, SSU and TEF 1 - α sequence dataset. Fuscostagonospora cytisi Jayasiri, Camporesi & K. D. Hyde, (MFLUCC 16-0622) and F. sasae Kaz. Tanaka & K. Hiray., (HHUF 29106) are selected as the outgroup taxa. Bootstrap support values for ML equal to or greater than 70 % and PP equal to or greater than 0.90 are given above the nodes. All type strains are in bold and newly-generated sequences are in red.

Figure 22. Split graphs showing the results of the pairwise homoplasy index (PHI) test of the new taxa and closely-related taxa using LogDet transformation and splits decomposition. a Leucaenicola coffeae; b Montagnula coffeae; c Xenodidymella coffeae; d Flabellascoma coffeae; e Longiostiolum coffeae; f Helminthosporium puerensis; g Neomassaria coffeae; h Neooccultibambusa coffeae; i Pararoussoella coffeae; j Cycasicola coffeae. PHI test result P-value (Φw) ≤ 0.05 indicates that there is significant recombination between the isolates included in the alignment. The new taxa are in red, “ T ” indicate the type species and each PHI test value and scale bars are given in the bottom right corner.