Clonostachys capitata

Clonostachys capitata Schroers, Stud. Mycol. 46: 87 (2001)

Index Fungorum number: IF485122; Facesoffungi Number: FoF13894

Saprobic on dead woody twigs of Magnolia henryi. Sexual morph: Ascomata 107–187 μm high × 88–166 μm diam., (x̅ = 144 × 124 μm, n = 5), perithecial, superficial, solitary or scattered, globose to subglobose, yellowish orange. Ostiole periphysate. Peridium 26–40 μm thick, composed of outer layers of hyaline to brownish yellow cells of textura angularis, and inner layers comprising hyaline cells of textura angularis. Paraphyses absent. Asci 68–89 × 8.4–11.8 μm (x̅ = 75.9 × 10.4 μm, n = 20), 8 spored, unitunicate, cylindrical, straight or curved, apically truncate, short pedicellate, with apical ring J--. Ascospores 13–17 × 5–6.5 μm (x̅ = 14.9 × 5.6 μm, n = 30), overlapping uniseriate, ellipsoidal, hyaline, 1 septate, constricted at the septum, the cells above central septum often broader than the lower ones, guttulate, spinulose, thick-walled, smooth, without a gelatinous sheath. Asexual morph: Undetermined.

Culture characteristics: Ascospores germinating on PDA within 24 h at room temperature (25 °C). Germ tubes produced from the apical cell of ascospore. Colonies on PDA, reaching 15 mm diameter after two weeks at 20–25 ℃, mycelia superficial, irregular, white, yellowish at the center, flat, undulate edge, white and yellowish granular on the surface, reverse light yellow.

Material examined: China, Yunnan Province, Lijiang, on dead woody twigs of Magnolia henryi (Magnoliaceae), 21 December 2019, G.C. Ren, KM08 (HKAS 122744), living culture KUMCC 21 0592.

Known distribution: On bark of an unidentified tree in Japan (Schroers 2001), on dead woody twigs of Magnolia henryi in China (This study).

GenBank numbers: SSU: OQ168235, LSU: OQ170884, ITS: OQ158962, tub2: OR578552.

Notes: The isolation obtained from dead woody twigs of Magnolia henryi is identified as Clonostachys capitata with support from both morphology and phylogeny. The new collection most resembles Clonostachys capitata (CBS 218.93) in having superficial, solitary to gregarious ascomata and clavate to subcylindrical asci with eight, ellipsoidal, single septate, spinulose ascospores (Schroers 2001). They are conspecific. Based on the known distribution and host of C. capitata, the new collection is reported as a saprobe on Magnolia henryi in Yunnan, China, for the first time.

Figure 1. Phylogram generated from ML analysis based on LSU, ITS, and tub2 sequence data, representing Bionectriaceae. Related sequences are obtained following Hyde et al. (2020b). Sixty-two strains are included in the combined analyses, which comprise 1922 characters for LSU, ITS, and tub 2 alignment. Nectriella nolinae (CBS 110134) and N. pironii (CBS 171.75) were used as the outgroup taxa. The best-scoring RAxML tree with a final likelihood value of 12223.574719 is presented. The matrix had 614 distinct alignment patterns, with 46.89% of undetermined characters or gaps. Estimated base frequencies were as follows; A = 0.220809, C = 0.269031, G = 0.262409, T = 0.247751; substitution rates AC = 1.147279, AG = 2.699630, AT = 1.218618, CG = 0.695890, CT = 4.229125, GT = 1.0000. The tree topology of the ML analysis is similar to the Bayesian analysis. Bootstrap values for ML equal to or greater than 70% and BYPP values greater than 0.95 (the rounding of values to 2 decimal proportions) are labelled on the nodes. Strains of the newly described species are in blue, while type strains are in bold.