Coryneum ilicis C.M. Tian & N. Jiang

Jiang, Ning, Voglmayr, Hermann & Tian, Cheng-Ming, 2019, Morphology and phylogeny reveal two novel Coryneum species from China, MycoKeys 56, pp. 67-80 : 67

Coryneum ilicis C.M. Tian & N. Jiang sp. nov. Figure 2

Diagnosis.

Coryneum ilicis is characterised by its host, Ilex pernyi , and large conidia with 10-11 distosepta.

Holotype.

CHINA. Shaanxi Province: Zhashui County, on branches of Ilex pernyi , 12 August 2017, N. Jiang (holotype: BJFC-S1720; ex-type culture from ascospore: CFCC 52994; living culture from conidium: CFCC 52996).

Etymology.

Named after the host genus on which it was collected, Ilex .

Description.

Associated with canker on branches of Ilex pernyi . Sexual morph: Pseudostromata 0.5-1.5 mm diam., typically distinct, circular, without perithecial bumps, containing 1 or 2 perithecia embedded in a well-developed entostroma. Central column and entostroma grey. Ostioles inconspicuous and often invisible at the surface of the ectostromatic disc. Perithecia (350 –)500–700(– 850) μm diam. (n = 20), globular, somewhat flattened at the base. Asci 110-155 × 13-20 μm, 8-spored, unitunicate, clavate, shortly pedicellate, apically rounded, with a conspicuous apical ring. Ascospores (26.2 –)29.7–35.5(– 36.2) × (11.0 –)11.8–14.3(– 15.2) μm, l/w = (1.9 –)2.2–2.9(– 3.2) (n = 50), 1-seriate, fusiform, ends pointed, uniseptate, constricted at the septa, hyaline, guttulate, smooth-walled. Asexual morph: Conidiomata acervular, 0.2-1 mm wide, 0.2-1.2 mm high, solitary, erumpent through the outer periderm layers of the host, scattered, surface tissues above slightly domed. Conidiophores 40-85 μm long, 3-7 μm wide, branched, cylindrical, septate, hyaline at the apex, pale brown at the base. Conidiogenous cells holoblastic, integrated, indeterminate, cylindrical, expanding towards the apices, pale brown, smooth, with 0-1 percurrent extensions. Conidia (82 –)87–95(– 105) × (9.5 –)10.5–11.5(– 12.5) μm, l/w = (7.4 –)7.7–9.1(– 9.3) (n = 50), variable in shape, curved, broadly fusiform to fusiform, cylindrical or clavate, dark brown, smooth-walled, 10-11-distoseptate, apical cell with a hyaline tip, truncate and black at the base.

Culture characters.

On PDA at 25 °C, colonies growing slowly and unevenly, reaching 70 mm diam. within 25 d, gradually becoming brownish dark grey in colour with scant cottony aerial mycelium, asexual morphs developed after 35 d.

Additional specimen examined.

CHINA. Shaanxi Province: Zhashui County, on branches of Ilex pernyi , 12 August 2017, N. Jiang (isotype: BJFC-S1721; living culture: CFCC 52995).

Notes.

Coryneum ilicis is the sole species known from the host genus Ilex ; it can be easily recognised by host association and phylogeny ( Fig. 1 ). Morphologically, conidia of Coryneum ilicis are larger and have more distosepta than in most of the other species (Table 1).

Figures

Figure 1. Phylogenetic tree based on an MP analysis of a combined DNA dataset of ITS, LSU, TEF 1 - α and RPB 2 gene sequences for the species of Coryneum. Bootstrap values ≥ 50 % for MP / ML analyses are presented at the branches. Scale bar = 50 nucleotide substitutions.

Figure 2. Coryneum ilex from Ilex pernyi (BJFC-S 1720, holotype) A Fruiting bodies on natural substrate in surface view B pseudostroma in transverse section, showing perithecia and gray entostroma C longitudinal sections through pseudostromata D ascus E-J ascospores K conidiophores L-N conidia. Scale bars: 1 mm (A); 0.5 mm (B, C); 20 μm (D); 10 μm (E-N).