Akanthomyces tiankengensis W.H. Chen, Y.F. Han, J.D. Liang & Z.Q. Liang, Microbiology Spectrum 10(5): e01975-22

Chen, Wan-Hao, Liang, Jian-Dong, Ren, Xiu-Xiu, Zhao, Jie-Hong & Han, Yan-Feng, 2023, Study on species diversity of Akanthomyces (Cordycipitaceae, Hypocreales) in the Jinyun Mountains, Chongqing, China, MycoKeys 98, pp. 299-315 : 299

Akanthomyces tiankengensis W.H. Chen, Y.F. Han, J.D. Liang & Z.Q. Liang, Microbiology Spectrum 10(5): e01975-22

Fig. 5

Description.

Spider host completely covered by white mycelium. Colonies on PDA, attaining a diameter of 27-28 mm after 14 days at 25 °C, white, consisting of a basal felt, floccose hyphal overgrowth; reverse yellowish. Hyphae septate, hyaline, smooth-walled, 2.4-2.6 μm wide. Conidiophores mononematous, hyaline, smooth-walled, with single phialide or whorls of 2 phialides. Phialides consisting of a cylindrical, somewhat inflated base, 16.2-25.3 × 2.1-2.9 μm, tapering to a thin neck. Conidia hyaline, smooth-walled, subglobose to ellipsoidal, 2.4-3.8 × 2.1-3.0 μm, forming divergent and basipetal chains. Sexual state not observed.

Strains and specimen examined.

China, Chongqing, Beibei District, Jinyun Mountain (29°50'22.14959"N, 106°23'18.0744"E). On a dead spider ( Araneae ), 1 May 2021, Wanhao Chen, GZAC CQ0581, living cultures, CQ05811 and CQ05812; GZAC CQ0517, living cultures, CQ05171 and CQ05172; GZAC CQ0501, CQ0509, CQ0510, CQ0512, CQ0516, CQ0558, CQ0582, CQ0586, CQ0598, CQ0590.

Remarks.

Strains CQ05811 and CQ05812 were identified as belonging to Akanthomyces , based on the phylogenetic analyses (Fig. 1 ) and clustered with A. tiankengensis in a subclade. The characteristics of CQ05811 and CQ05812 were very closely linked with A. tiankengensis , which had fusiform conidia (2.3-3.0 × 1.5-2.3 μm) and shorter phialide (13.9-17.1 × 1.1-1.6 μm). Furthermore, the pairwise dissimilarities of ITS sequences show 3 bp difference within 569 bp between CQ05811 and A. tiankengensis (0.52%) and no difference within 569 bp between CQ05171, CQ05172 and A. tiankengensis . Thus, molecular phylogenetic results and morphologically based conclusions supported the idea that strains CQ05811, CQ05812, CQ05171 and CQ05172 were A. tiankengensis .

Figures

Figure 1. Phylogenetic relationships amongst the new strains and their allies based on multigene dataset (ITS, LSU, RPB 2 and TEF). Statistical support values (≥ 70 % / 0.95) are shown at the nodes for ML bootstrap support / BI posterior probabilities.

Figure 5. Akanthomyces tiankengensis A infected spider (Araneae) B, C PDA culture plate showing reverse (B) and top (C) sides of the colony D-J phialides and conidia. Scale bars: 10 mm (B, C); 10 μm (D-J).