Nigropunctata khalidii Y.P. Wu & Q.R. Li

Tun, Zaw Lin, Gomdola, Deecksha, Maharachchikumbura, Chitrabhanu S. Bhunjun Sajeewa S. N., Alotibi, Fatimah & Hyde, Kevin D., 2024, A novel species and a new geographical record of Nigropunctata from Bambusa vulgaris in northern Thailand, Phytotaxa 676 (2), pp. 155-168 : 162

Nigropunctata khalidii Y.P. Wu & Q.R. Li , in Li et al., Mycosphere 15(1): 334 (2024) ( Fig. 3 )

Index Fungorum number: IF 850423, Facesoffungi number: FoF 16952

Saprobic on dead branches of Bambusa vulgaris . Sexual morph: Ascomata 500–560 × 590–610 μm (x̄ = 526 × 606 μm, n = 5), immersed, unilocular, solitary or gregarious, perithecial, globose to subglobose, ostiolate. Ostioles 120–130 × 70–90 μm wide (x̄ = 123 × 82 μm, n = 5), central, filled with periphyses, covered with black, thick-walled clypeus. Ectostroma yellow. Peridium 95–160 μm wide (x̄ = 122 μm, n = 5), comprising two layers; outer layer composed of dark brown, thick-walled cells of textura angularis, inner layer composed of hyaline, thin-walled cells of textura angularis. Paraphyses 3–4 μm (x̄ = 3.5 μm, n = 20) wide, longer than asci, numerous, filamentous, sinuous, septate, constricted at septa, guttulate, embedded in a gelatinous matrix. Asci 80–200 × 11.5–23 μm (x̄ = 163 × 19 μm, n = 20), unitunicate, 8-spored, cylindrical to clavate, comprising a short pedicel, rounded and sometimes narrower at the apex with a J +, apical ring. Apical ring 5.5–7 μm (x̄ = 6 μm, n = 10), discoid. Ascospores 17–25 × 7–10 μm (x̄ = 21.4 × 7.9, n = 20), uni-seriate, hyaline to dark brown, smooth-walled, cylindrical or broadly ellipsoidal or fusiform, aseptate, comprising a central or multiple smaller guttules, the ascospores covered with a thick mucilaginous sheath. Sheath 3–4 μm thick (x̄ = 3.9 μm, n = 10). Germ slit on ventral side of the ascospore, straight, along the entire spore length. Asexual morph: Not observed.

Culture characteristics:—Colonies on MEA reaching 1 cm diam. after 2 weeks, incubated at 25 °C; colonies from above white, flat, with irregular margins, and slightly cottony; colonies from reverse yellowish.

Material examined:— Thailand, Chiang Rai Province, Mae Fah Luang University Campus, on fallen dead branches of Bambusa vulgaris ( Poaceae ), 15 September 2022, Z. L. Tun, ZL138 ( MFLU 23-0382); living culture ( MFLUCC 23-0237).

Distributions: — China ( Li et al. 2024), Thailand (This study).

GenBank accession numbers: — ITS = OR909613, β-tub = PQ397546, rpb2 = OR757299 and tef-1α = PQ505631.

Notes:—Our isolate ( MFLUCC 23-0237) clusters with the type of N. khalidii (GMB1156) with 100% ML and 1 PP statistical support ( Fig. 1 ). The morphology of our isolate ( MFLUCC 23-0237) is similar to that of N. khalidii (GMB1156) . The ascospores of N. khalidii (GMB1156 and MFLUCC 23-0237) are brown to dark brown ( Li et al. 2024). The asci length of our isolate ( MFLUCC 23-0237) is 80–200 µm while those of the type of N. khalidii (GMB1156) is 146–173 µm. The ascospore width of N. khalidii ( MFLUCC 23-0237 and GMB1156) is also similar (17–25 µm vs. 14.8–18 µm). However, the ascospores of N. khalidii (GMB1156) lack a germ slit ( Li et al. 2024), but the ascospores of our isolate ( MFLUCC 23-0237) has a germ slit.

Upon comparison of the intra-species genetic distances between the two strains of N. khalidii , 0.4% (410 bp) and 2.3% (430 bp) differences were observed across ITS and β-tub sequences. Considering the insignificant intra-species differences, similar morphological characteristics and phylogenetic analyses, we identify MFLUCC 23-0237 as N. khalidii . This is the first report of N. khalidii from Thailand. Here, we also provide rpb2 and tef-1α sequence data for N. khalidii .

Figures

FIGURE 1. Phylogramgenerated from IQ-analysisbasedon thecombined ITS,LSU,β-tub,rpb2and tef-1α sequences ofPallidoperidiaceae taxa, and a few representative taxa that belong to Gyrothricaceae. Selenodriella brasiliana (CBS 140236 and CBS 140227), S. cubensis (CBS 683.96), and S. fertilis (CBS 148328 and CPC 16273) were selected as outgroups. Bootstrap support values (ML ≥ 70%) and Bayesian posterior probabilities (PP ≥ 0.95) are given at respective nodes. A hyphen (-) represents support values below 70% (ML) and 0.95 (PP). Type strains are indicated with T, and our isolates are in red.

FIGURE 3. Nigropunctata khalidii (MFLU 23-0382) a Substrate. b Appearance of ascomata on the host surface. c, d Vertical sections through ascomata. e Peridium. f Paraphyses. g J+ Apical ring turning blue in Melzer’s reagent. h, i Immature and mature asci. j–m Immature and mature ascospores. n Ascospore with a germ slit. o Germinated ascospore. p, q Front and reverse colony on MEA. Scale bars: b, c = 200 μm, d, e = 50 μm, f, g = 5 μm, h, i = 20 μm, j–o = 10 μm.