Ctenomyces albus Y.F. Han, Z.Q. Liang & Z.Y. Zhang

Zhang, Zhi-Yuan, Han, Yan-Feng, Chen, Wan-Hao & Liang, Zong-Qi, 2019, Phylogeny and taxonomy of three new Ctenomyces (Arthrodermataceae, Onygenales) species from China, MycoKeys 47, pp. 1-16 : 1

Ctenomyces albus Y.F. Han, Z.Q. Liang & Z.Y. Zhang sp. nov. Figure 3

Holotype.

CHINA, Guizhou Province, on soil, Sept. 2016, Z.Y. Zhang (HMAS 255389, holotype, ex-type culture CGMCC 3.19232).

Paratypes.

CHINA, Guizhou Province, on soil, Sept. 2016, Z.Y. Zhang, dried cultures HMAS 255442 and HMAS 255443, isolates CGMCC 3.18631 (GZUIFR-QL17.11) and CGMCC 3.18632 (GZUIFR-QL17.12).

Etymology.

Referring to the white colony.

Description.

Aerial hyphae hyaline, smooth, septate, branched, 1.1-2.4 μm wide; racquet hyphae absent. Terminal and lateral conidia borne on hyphae, short protrusions, side branches or an ampulliform swelling. Conidia solitary or in series of up to 2-3 conidia connected by short and slim hypha, ellipsoid, smooth- or rough-walled, verrucose, 12.8-18.6 × 10.8-14.7 μm (x‒ = 15.4 × 12.5 μm, n=15). Intercalary conidia present, subglobose or ellipsoidal, smooth- or rough-walled, 13.1-16.9 × 11.2-14.4 μm (x‒ = 14.5 × 12.6 μm, n=15).

Culture characteristics.

Colonies on PDA growing in the dark reaching 32 mm diam. in 14 d at 25 °C, white, short fluffy to powdery, appearing some annulations, rounded, margin regular and defined. Reverse yellowish.

Notes.

Ctenomyces albus is distinct from other species as it is the only species with intercalary conidia in the genus. In addition, our ITS and polygenic phylogeny showed that three isolates of C. albus were in a clade sister to C. serratus (Figures 1, 2) and clearly separate from other species. Following Jeewon and Hyde’s (2016) guidelines on new species delimitation, there were 37 bp (base pair) differences amongst 508 nucleotides ITS sequences between the isolate CGMCC 3.19232 and C. serratus CBS 187.61 (only ITS sequence data are available, EF1A and RPB2 are lacking), which also supports them as distinct different species. Therefore, we introduce C. albus sp. nov. in this study.