Aquadictyospora yunnanensis L. Lu, M.Y. Han & Tibpromma, 2024

Han, Meiyan, Lu, Li, Karunarathna, Samantha C., Zheng, Dege, Elgorban, Abdallah M. & Tibpromma, Saowaluck, 2024, Morpho-molecular analyses reveal Aquadictyospora yunnanensis sp. nov. from coffee (Coffea arabica) in Yunnan Province, China, Phytotaxa 674 (3), pp. 239-251 : 244-246

Aquadictyospora yunnanensis L. Lu, M.Y. Han & Tibpromma , sp. nov. Fig. 2

Index Fungorum number: IF902532, Facesofungi number: FoF16620

Etymology:— The name reflects the location, “ Yunnan ” Province, where the holotype was collected. Holotype:— MHZU 22-0148

Saprobic on dead branch of Coffea arabica ( Rubiaceae ). Sexual morph: Undetermined. Asexual morph: Hyphomycetous. Colonies on natural substrate 150–300 × 110–250 μm (x̄ = 211 × 170 μm, n = 10), superficial, forming sporodochial conidiomata, dark brown to black, velvety, scattered, circular or subglobose in small groups, crowded and confluent when older, with base attached on surface of host plant. Mycelium 2–3 μm wide, immersed, septate, branched and hyaline hyphae. Conidiophores micronematous, reduced to conidiogenous cell, hyaline to pale brown. Conidiogenous cells holoblastic, solitary, determinate. Conidia 25–40 × 15–20 μm (x̄ = 33 × 17.5 μm, n = 30), dictyosporous, oval to obovoid, compactly adpressed 2–4 apically rows of cells, guttulate, with hyaline and subglobose or ovoid basal cell connecting cell, 10–15 × 9–11 μm (x̄ = 12 × 10 μm, n = 30), not complanate, secession involves splitting of the basal, without appendages or mucilaginous sheath.

Culture characteristics:— Colonies on PDA reaching 50 mm diam. after two months at 25 °C. Cultures from above yellow white, dense, circular, papillate with fairly fluffy, covered with white aerial mycelium; reverse dark brown at the center, edge reddish brown.

Material examined:— China, Yunnan Province, Jinghong City, a decaying branch of Coffea arabica , (101°2'44'' E, 22°31'18'' N, 856.89 m), 15 September 2021, LiLu, JHPW7 (MHZU 22-0148, holotype), ex-type living culture ZHKUCC 22-0279, other living culture ZHKUCC 22-0280.

GenBank numbers:— ITS: OQ544398, LSU: OQ544396, rpb 2: OQ556793, SSU: OQ544400, tef 1-α: OQ556795 (ZHKUCC 22-0279, ex-type); ITS: OQ544399, LSU: OQ544397, rpb 2: OQ556794, SSU: OQ544401, tef 1-α: OQ556796 (ZHKUCC 22-0280).

Notes:— In phylogeny, our new species ( Aquadictyospora yunnanensis ) formed a well-separated lineage sister to A. clematidis (MFLUCC 17-2080) with 94% ML/1.00 BYPP statistical support ( Fig. 1 ). Based on nucleotide comparisons, A. yunnanensis (ZHKUCC 22-0279) is different from A. clematidis (MFLUCC 17-2080, type) by 23/559 bp (4.1%, without gap) of the ITS, 5/838 bp (0.6%, without gap) of the LSU, 56/871 bp (6.4%, without gap) of the rpb 2, 4/899 bp (0.4%, without gap) of the SSU and 48/913 bp (5.2%, without gap) of the tef 1-α. Regarding morphological characteristics, our collection is similar to A. clematidis in having brown conidia with a basal cell ( Phukhamsakda et al. 2020). However, the difference between our new species and A. clematidis is that our strain has light brown conidia, is compactly adpressed, and has 2–4 apical rows of cells, while A. clematidis has reddish brown conidia, broadly rounded and heavily pigmented in the upper half ( Phukhamsakda et al. 2020). Therefore, we introduce A. yunnanensis as a new species based on morphology and multigene phylogenetic analysis.

Figures

FIGURE 1. RAxML tree based on a combined dataset of ITS, LSU, SSU, tef1-α, and rpb2 gene sequences. Bootstrap support values for ML equal to or greater than 60% and BYPP equal to or greater than 0.90 are given above the nodes. Newly generated sequences are in red, and type strains are in bold.

FIGURE 2.Aquadictyospora yunnanensis (MHZU 22-0148,holotype).a,b.Sporodochia on naturalsubstrate.c.Sectionof sporodochium. d–i. Mature conidia attached with basal cells. j–m. Mature conidia. n. Germinated conidium. o. Culture on PDA from above and reverse. Scale bars: b = 100 μm, c = 30 μm, d = 15 μm, e–n = 10 μm.