Neooccultibambusa 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-

Neooccultibambusa coffeae L. Lu & Tibpromma sp. nov.

Fig. 16

Etymology.

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

Diagnosis.

Differs from N. chiangraiensis and N. kaiyangensis X. D. Yu, S. N. Zhang & Jian K. Liu by the greyish-green ascospores.

Holotype.

HKAS 137604 .

Description.

Saprobic on decaying branch of C. arabica . Teleomorph: Ascomata 140–180 × 200–250 µm (x- = 156 × 218 µm, n = 10), superficial to semi-immersed, solitary to gregarious, small, black spots on host surface, unilocular, globose or subglobose, some with ostiolate. Peridium 10–20 µm wide (x- = 15 µm, n = 20), outer walls comprising 2–4 layers of textura angularis cells, brown to dark brown, inner walls thin, hyaline and density. Hamathecium 2–4 µm wide (x- = 3.2 µm, n = 20), hyphae-like, hyaline, filiform, branched, pseudoparaphyses numerous. Asci 100–200 × 20–30 µm (x- = 156 × 24 µm, n = 20), 8 - spored, bitunicate, cylindrical-clavate, straight, with a short furcate, apically rounded, with an ocular chamber. Ascospores 30–40 × 8–12 µm (x- = 36.6 × 10.3 µm, n = 50), overlapping biseriate, hyaline when young, greyish-green when mature, fusoid or elliptical, 1–3 - septate, guttulate, smooth-walled, mucilaginous sheath present. Anamorph: Not observed.

Culture characteristics.

Ascospores germinating on PDA within 24 h, colonies reached 4 cm in diameter after two months at 25 ° C, mycelia superficial, filamentous, with filiform margin, flat, smooth, from above, brown at the centre, dark brown at the edge, from below, dark brown.

Materials examined.

China, Yunnan Province, Xishuangbanna, Pu’wen Town , on a decaying branch of Coffea arabica ( Rubiaceae ) (22°31'18"N, 101°2'44"E, 850 m alt.), 15 September 2021, LiLu, JHPW 13 ( HKAS 137604 , holotype), isotype MHZU 23-0056 , ex-type living culture KUNCC 24-18351 , ex-isotype living culture ZHKUCC 23-0622 ; China, Yunnan Province, Pu’er , on a decaying branch of C. arabica , (22°36'2"N, 101°0'59"E, 1015 m alt.), 16 September 2021, LiLu, Pu’er 1-5 ( HKAS 137603 , paratype), isoparatype MHZU 23-0057 , ex-paratype living culture KUNCC 24-18353 , ex-isoparatype living culture ZHKUCC 23-0624 .

Notes.

In the concatenated phylogenetic analysis, Neooccultibambusa coffeae forms a distinct lineage within Neooccultibambusa , closely related to N. chiangraiensis and N. kaiyangensis (Fig. 17 ). Morphologically, the new species resembles N. chiangraiensis and N. kaiyangensis in shape, but differs in the colour of ascospores. The ascospores of N. coffeae are greyish-green when mature, while the ascospores of N. chiangraiensis and N. kaiyangensis are pale brown (Fig. 16 ; Doilom et al. (2017); Yu et al. (2021)). Based on nucleotide comparisons, N. coffeae ( ZHKUCC 23-0622 ) is different from N. chiangraiensis ( MFLUCC 12-0559 ) by 50 / 494 bp (10 %, without gaps) of the ITS, 22 / 872 bp (2.5 %, without gaps) of the LSU, 16 / 943 bp (1.6 %, without gaps) of the SSU and 32 / 613 bp (5 %, without gaps) of the TEF 1 - α; In comparison, it is different from N. kaiyangensis ( CGMCC 3.20404 ) in 42 / 467 bp (9 %, without gaps) of the ITS, 20 / 836 bp (2 %, without gaps) of the LSU, 16 / 1009 bp (1.5 %, without gaps) of the SSU, 42 / 963 bp (4 %, without gaps) of the TEF 1 - α and 88 / 886 bp (10 %, without gaps) of the RPB 2. In the BLASTn NCBI GenBank database search of ITS, LSU, SSU, RPB 2 and TEF 1 - α sequences, ITS results are similar to Brunneofusispora hyalina M. S. Calabon & K. D. Hyde , ( MFLU 21-0016 ) with 90 % similarity, LSU is similar to N. trachycarpi X. D. Yu, S. N. Zhang & Jian K. Liu , ( CGMCC 3.20405 ) with 98 % similarity, SSU is similar to Roussoella sp. ( GMB 1323 ) with 93 % similarity, RPB 2 and TEF 1 - α results are similar to N. kaiyangensis ( MFLUCC 17-2128 ) with 90 % and 96 % similarity, respectively. In addition, the PHI test results (Fig. 22 h ) revealed no significant recombination relationships between N. coffeae and its phylogenetically related taxa. The morphological differences and phylogenetic analyses support the introduction of N. coffeae as a new species.

Figures

Figure 16. Neooccultibambusa coffeae (HKAS 137604, holotype). A, B ascomata on a decaying branch of C. arabica; C longitudinal section of an ascoma; D peridium wall; E pseudoparaphyses; F – J asci; L – O ascospores; P an ascospore stained with Indian ink; K germinated ascospores; Q culture on PDA from obverse and reverse. Scale bars: 50 μm (C); 20 μm (D, E, K – P); 30 μm (F – J).

Figure 17. Phylogram generated from the best scoring RAxML tree, based on a combined ITS LSU, SSU, RPB 2 and TEF 1 - α sequence dataset. Ohleria modesta Fuckel, (CBS 141480 and MGC) 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.