Samsoniella coleopterorum W.H. Chen, Y.F. Han & Z.Q. Liang, 2020

Chen, Wan-Hao, Han, Yan-Feng, Liang, Jian-Dong, Tian, Wei-Yi & Liang, Zong-Qi, 2020, Morphological and phylogenetic characterisations reveal three new species of Samsoniella (Cordycipitaceae, Hypocreales) from Guizhou, China, MycoKeys 74, pp. 1-15 : 1

Samsoniella coleopterorum W.H. Chen, Y.F. Han & Z.Q. Liang sp. nov. Fig. 3

Diagnosis.

Differs from Samsoniella aurantia by having smaller conidia and snout beetle host in the family Curculionidae . Differs from S. lepidopterorum by having cylindrical to ellipsoidal phialides, smaller fusiform to ellipsoidal conidia and a different host.

Type.

China, Guizhou Province, Xishui County (28°29'56.70"N, 106°24'31.04"E), July 2018, Jiandong Liang, holotype GZAC A1950, ex-type culture GZAC A19501. Sequences from isolated strain A19501 have been deposited in GenBank with accession numbers: ITS = MT626376, RPB1 = MT642600, RPB2 = MN101585 and TEF = MN101586.

Description.

Colonies on PDA, 3.6-4.0 cm diam. in 14 d at 25 °C, white, consisting of a basal felt and cottony, floccose hyphal overgrowth, reverse yellowish. Prostrate hyphae smooth, septate, hyaline, 1.1-1.8 μm diam. Erect conidiophores usually arising from aerial hyphae, Isaria -like with phialides in whorls of two to four. Phialides 5.4-9.7 × 1.2-1.8 μm, with a cylindrical to ellipsoidal basal portion, tapering into a short distinct neck. Conidia in chains, hyaline, fusiform, ellipsoidal or subglobose, one-celled, 1.7-2.5 × 1.2-1.8 μm. Chlamydospores and synnemata not observed. Size and shape of phialides and conidia similar in culture and on natural substratum. Sexual state not observed.

Host.

Snout beetle, family Curculionidae .

Distribution.

Xishui County, Guizhou Province, China.

Etymology.

Referring to its insect host, order Coleoptera .

Remarks.

Samsoniella coleopterorum was easily identified as belonging to Samsoniella based on the phylogenetic analyses (Fig. 1 ). Comparing with the typical characteristics of three species (Table 2 ), S. coleopterorum has a close relationship with S. aurantia by having cylindrical to ellipsoidal phialides and similar in size. However, it differs from S. aurantia by having shorter conidia and snout beetle host in the family Curculionidae . Based on the combined dataset of ITS, RPB1, RPB2 and TEF sequences, S. coleopterorum has a close relationship with S. lepidopterorum (Fig. 2 ). However, S. coleopterorum has cylindrical to ellipsoidal phialides, smaller fusiform to ellipsoidal conidia and a different host.

Figures

Figure 1. Phylogenetic relationships of the genus Samsoniella in Cordycipitaceae, based on multigene dataset (ITS, RPB 1, RPB 2 and TEF). Statistical support values (≥ 50 % / 0.5) are shown at the nodes for ML bootstrap support / BI posterior probabilities.

Figure 2. Phylogenetic relationships between the genus Samsoniella and closely-related species, based on multigene dataset (ITS, RPB 1, RPB 2 and TEF). Statistical support values (≥ 50 % / 0.5) are shown at the nodes for ML bootstrap support / BI posterior probabilities.

Figure 3. Samsoniella coleopterorum A infected insect (Coleoptera) B, C top (B) and underside (C) of a colony cultured on PDA medium at 14 d D, E, F, G, I phialides and conidia in chains J conidiophore and phialides H conidia. Scale bars: 10 mm (B, C); 10 μm (D-J).