Anthosulcatispora heveae R.F. Xu, K.D. Hyde & Tibpromma, 2025

Xu, Rui-Fang, Karunarathna, Samantha C., Hyde, Kevin D., Kakumyan, Pattana, Elgorban, Abdallah M., Phukhamsakda, Chayanard & Tibpromma, Saowaluck, 2025, Morphology and multigene phylogeny reveal a new species and a new record of saprobic Dothideomycetes from Hevea brasiliensis in Yunnan Province, China, Phytotaxa 690 (1), pp. 63-76 : 68-69

Anthosulcatispora heveae R.F. Xu, K.D. Hyde & Tibpromma , sp. nov ( Fig. 3 )

Index Fungorum Number: IF 903279; Facesoffungi Number: FoF 17273

Holotype: GMB-W1101

Etymology: named after the host genus, Hevea .

Saprobic on dead branch of Hevea brasiliensis . Sexual morph: Ascomata 160–420 μm ×160–390 μm, (x̄ = 301 × 313 µm, n = 10), pyriform, solitary, uniloculate, immersed, indistinguishable from host tissue, brown, ostiolate. Ostioles 80–230 × 70–140 μm (x̄ = 125 × 109 μm, n = 5), central, papillate, irregular wall, filled with hyaline paraphyses. Peridium 20–50 μm wide, composed of two layers, inner layer pale-brown, comprising 2–3 cell layers, arranged in a textura angularis, outer layer brown cells, thick-walled, textura prismatica. Hamathecium comprising 1–2 μm wide, numerous filamentous, unbranched, aseptate, embedded in a hyaline gelatinous matrix, cellular pseudoparaphyses. Asci 80–115 × 9–13 μm (x̄ = 95 × 11 μm, n = 20), 8-spored, bitunicate, cylindrical to clavate, straight or slightly curved, short pedicellate, apically rounded, thick-walled. Ascospores 15–25 × 5–7 μm (x̄ = 21 × 6 μm, n = 30), overlapping, 2-seriate, fusiform, 1-septate in the middle of cell, widest at the central and tapering towards narrow ends, constricted at the septum, hyaline, big guttules, with thick mucilaginous sheath, and smooth-walled. Asexual morph: Undetermined.

Culture characteristics: Ascospores germinated on PDA within 24h. Colonies growing slowly on PDA, flat, undulate, culture from above, white, flossy, reverse brown at the center, curled margin, white at the edge.

Material examined: China, Yunnan Province, Lincang , Yongde County, on a dead branch of Hevea brasiliensis , 28 July 2022, Rui-Fang Xu, LCR09 (GMB-W1101, holotype) ; ex-type living culture GMBCC 1090, additional living culture GMBCC 1091.

GenBank numbers: GMBCC 1090 = ITS: PQ728788, LSU: PQ728790, SSU: PQ728792, tef 1-α: PQ757610; rpb 2: PQ757607; GMBCC 1091 = ITS: PQ728789, LSU: PQ728791, SSU: PQ728793, tef 1-α: PQ757611, rpb 2: PQ757608.

Notes: Based on phylogenetic analyses of combined ITS, LSU, SSU, tef 1-α, and rpb 2, the new strain clustered within Anthosulcatispora and formed a separate lineage with Anthosulcatispora brunnea (MFLU 18-1393) and A. subglobosa (MFLUCC 17-2065) ( Fig. 1 ). Anthosulcatispora heveae and A. brunnea differ in having larger ascomata (161–416 × 163–390 μm vs. 80–205 × 90–260μm), larger asci (80–114 × 9–13 μm vs. 70–90 × 8–10 μm), larger ascospores (18–23 × 5–7 μm vs. 11–18 × 5–6 μm) in A. heveae , further, in A. heveae , the ascospores are fusiform, hyaline with large guttules, with a mucilaginous sheath. Ascospores of A. brunnea are oblong to ellipsoidal, brown to dark brown, and do not have a mucilaginous sheath ( Phookamsak et al. 2019; Phukhamsakda et al. 2020). Moreover, the base pair comparison of A. heveae and A. brunnea shows 59/557 bp differences in ITS (10.59%, gaps 10 bp), and 14/813 bp differences in LSU (1.72%). Anthosulcatispora subglobosa has an asexual morph but no sexual morph, while A. heveae only has a sexual morph and no asexual morph. Therefore, we cannot compare the differences between the two species.

In the comparison of nucleotide sequences of A. heveae and A. subglobosa , we have observed 23/537 (with 12 gaps) base pair differences (4.28%) in ITS, 4/854 base pair differences (0.47%) in LSU, 2/881 base pair differences (0.23%) in SSU, 40/892 base pair differences (4.48%) in tef 1-α, and 21/748 base pair differences (2.81%) in rpb 2. According to Jeewon & Hyde (2016), a minimum of more than 1.5% nucleotide changes in the ITS region indicates the presence of a novel species. Therefore, we introduce A. heveae 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 0.95 are given above/below the nodes. Newly generated sequences are in red.

FIGURE 3. Anthosulcatispora heveae (GMB-W1101, holotype). a, b Habit on substrate. c Section of ascoma. d Pseudoparaphyses. e Peridium. f–j Asci. k Germinated ascospore. l–q Ascospores. r Ascospore with mucilaginous sheath. s, t Colonies on PDA media. Scale bars: c = 200 μm, d, f–k, r = 30 μm, l–q = 10 μm.