Dothiorella zanthoxyli L.W. Li & Jian K. Liu, 2023

Li, Wen-Li, Liang, Rui-Ru, Dissanayake, Asha J. & Liu, Jian-Kui, 2023, Botryosphaerialean fungi associated with woody oil plants cultivated in Sichuan Province, China, MycoKeys 97, pp. 71-116 : 71

Dothiorella zanthoxyli L.W. Li & Jian K. Liu sp. nov.

Fig. 14

Etymology.

The epithet ‘‘ zanthoxyli ’’ refers to the host genus Zanthoxylum , on which the holotype was collected.

Holotype.

HKAS 125893.

Description.

Saprobic on decaying branches of Zanthoxylum bungeanum . Sexual morph: Ascomata 258-280 × 170-174 μm (x̄ = 269 × 172 μm, n = 10), submerged in the substrate, partly erumpent at maturity, solitary or gregarious, dark brown to black, subglobose, unilocular. Ostiole 42-44 μm diam., central. Peridium 35-40 μm wide, thick-walled, outer layers composed of 3-5 layers dark brown cells of textura angularis, becoming hyaline towards the inner region. Pseudoparaphyses 3-4.5 μm wide, hyaline, frequently aseptate. Asci 63.5-77 × 20-24.5 μm (x̄ = 70 × 22.5 μm, n = 30), short stipe, clavate, thick-walled, bitunicate, 8-spored, irregularly biseriate. Ascospores 22.5-25 × 9.5-11 μm (x̄ = 24 × 10 μm, n = 30), L/W ratio = 2.6, oblong, ovate to sub-clavate, (0-)1-septate, slightly constricted at the septum, hyaline to dark brown, moderately thick-walled, straight or inequilateral, basal cell tapering towards the acute end. Asexual morph: Not observed.

Culture characteristics.

Ascospores germinate on PDA within 12 h. Colonies growing on PDA, reaching a diameter of 4 cm after five days at 25 °C, effuse, velvety, with entire to slightly undulate edge. Surface initially white and later turning dark olivaceous from the surrounding of the colony. Dark gray in reverse.

Materials examined.

China, Sichuan Province, Yanan City , Hanyuan County, 29°16'51"N, 102°37'48"E, elevation 1,689 m, on dead branches of Zanthoxylum bungeanum ( Rutaceae ), 30th October 2021, W.L Li, 504 (HKAS 125893, holotype), ex-type living culture UESTCC 22.0082 = CGMCC 3.24159 ; ibid., 506 (HUEST 22.0084), living culture UESTCC 22.0083 ; ibid., 507 (HUEST 22.0085), living culture UESTCC 22.0084. Additional sequences: LSU: OQ164839 (CGMCC 3.24159), OQ164840 (UESTCC 22.0083), OQ164841 (UESTCC 22.0084) .

Notes.

Three strains of Dothiorella zanthoxyli isolated from Zanthoxylum bungeanum correspond well with sexual morph of Dothiorella described by Phillips et al. (2013), but morphologically differ from other species ( Do. camelliae , Do. iberica and Do. sarmentorum ) in the size of ascomata and asci (Table 3 ). A comparison of ITS and tef1 nucleotides shows that Do. zanthoxyli is significantly different from its sister species, Do. camelliae by 4/550 bp (0.72%) in ITS and 14/242 bp (5.8%) in tef1. In the phylogenetic analysis, these two species formed two distinct clades in Dothiorella (Fig. 4 ).

Figures

Figure 4. Phylogram generated from RAxML analysis based on combined ITS, tef 1 and tub 2 sequence data of Dothiorella isolates. The tree was rooted to Neofusicoccum luteum (CBS 562.92 and CMW 41365). The ML (≥ 75 %) and BI (≥ 95 %) bootstrap supports are given near the nodes, respectively. Isolates from this study are marked in red and ex-type strains are marked in bold.

Figure 14. Dothiorella zanthoxyli (HKAS 125893, holotype) a, b appearance of ascomata on natural substrate c vertical section of ascoma d ostiole e section of peridium f, k-n asci g-j brown ascospores. Scale bars: 50 μm (c); 20 μm (d-f); 10 μm (g-n).