Samsoniella hepiali (Q.T. Chen & R.Q. Dai ex R.Q. Dai et al.) H. Yu, R.Q. Dai, Y.B. Wang, Y. Wang & Zhu L. Yang

Wang, Yao, Wang, Zhi-Qin, Thanarut, Chinnapan, Dao, Van-Minh, Wang, Yuan-Bing & Yu, Hong, 2023, Phylogeny and species delimitations in the economically, medically, and ecologically important genus Samsoniella (Cordycipitaceae, Hypocreales), MycoKeys 99, pp. 227-250 : 227

Samsoniella hepiali (Q.T. Chen & R.Q. Dai ex R.Q. Dai et al.) H. Yu, R.Q. Dai, Y.B. Wang, Y. Wang & Zhu L. Yang

Fig. 5

Type.

China (holotype: IMM 82-2 = CHICMM 82-2; ex-type living culture: ICMM 82-2).

Description.

Teleomorph: Stromata from the whole body of lepidopteran pupae, gregarious, generally unbranched, up to 5-23 mm long. Stipes fleshly, flexuous or erect, yellowish to orange, cylindrical to clavate, 2.5-15.5 × 0.9-4.6 mm. Fertile parts orange, clavate, lateral side usually have a longitudinal section without producing perithecia, 1.3-8.5 × 0.8-5.2 mm. Perithecia crowded, superficial, narrowly ovoid to fusiform, 277.9-355.3 × 116.3-199.6 µm. Asci hyaline, cylindrical, 8-spored, 145-300 × 3.5-5 μm. Apical caps prominent, hemiglobose, 2.5-4 µm wide, 2.4-3.2 µm high. Ascospores hyaline, bola-shaped, septate, 120-240 × 0.8-1.5 μm. Anamorph: See Wang et al. (2020a). The following descriptions are based on other specimens examined from Vietnam. Synnemata arising from the whole body of lepidopteran pupae, branched or unbranched, 5-20 mm long. Stipes cylindrical or clavate, 0.6-4.2 mm wide, with powdery conidia at the apex, white to yellowish. Colonies on PDA moderately fast-growing, 32-45 mm diameter in 14 days at 25 °C, white to yellowish, cottony, with high mycelial density, reverse white to pale yellow, turning orange when old. Hyphae smooth-walled, branched, septate, hyaline, 0.9-2.3 µm wide. Conidiophores smooth-walled, cylindrical, solitary, 3.9-10.2 × 1.5-1.9 µm. Phialides on conidiophores verticillate, usually in whorls of two to five, or solitary on hyphae, 5.7-10.9 µm long, basal portion cylindrical to narrowly lageniform, tapering gradually or abruptly toward the apex, from 1.4-1.9 µm wide (base) to 0.5-0.9 µm wide (apex). Conidia smooth and hyaline, fusiform or oval, one-celled, 1.9-2.8 × 1.0-1.6 µm, often in chains. Size and shape of phialides and conidia similar in culture and on natural substratum.

Distribution.

Yunnan, Qinghai, Anhui and Guizhou Province, China; Lao Cai Province, Vietnam; Buenos Aires City, Argentina.

Materials examined.

Vietnam, Lao Cai Province, Sa Pa District, Hoang Lien Mountains (22°21′10″N, 103°46′29″E, 1989 m above sea level), on pupae of Hepialidae buried in soil, 30 October 2016, collected by Hong Yu (YHH 868, YHH 897-YHH 899; living culture: YFCC 868, YFCC 897-YFCC 899) .

Commentary.

The strain (YFCC 868) isolated from the pupa of Hepialidae from Vietnam formed a well-supported clade with S. hepiali ex-type isolate (ICMM 82-2) (Fig. 2 ). Based on microscopic observation, the strain YFCC 868 displayed typical morphological characteristics of anamorphs found in species of Samsoniella . For YFCC 868, the size and shape of phialides and conidia were similar to those of S. hepiali as described by Wang YB et al. (2020b). Both morphological study and phylogenetic analyses supported the isolate YFCC 868 as being S. hepiali .

In the current study, the sexual morph of S. hepiali was first reported. As for other teleomorph species of Samsoniella , S. hepiali has fleshy stromata, clavate fertile parts, superficial perithecia, and cylindrical asci with bola-shaped ascospores. Among these species, only three, namely, S. cardinalis , S. hepiali , and S. kunmingensis , have short stromata ( Wang et al. 2020a; Wang et al. 2022). However, S. hepiali differs from S. cardinalis and S. kunmingensis by having abundant stromata extruded from the entire body of lepidopteran insects and by having clavate fertile parts with orange color.

Figures

Figure 2. Phylogenetic tree of Samsoniella based on Bayesian inference and Maximum Likelihood analyses of a 4 - locus (5 P _ TEF, 3 P _ TEF, RPB 1 and MCM 7) dataset. No significant differences in topology are observed between BI and ML (IQ-TREE) phylogenies. Numbers at the branches indicate support values (BI-PP / RAxML-BS / IQ-TREE-BS) above 0.7 / 70 % / 70 %. Isolates in bold type are those analyzed in this study.

Figure 5. Samsoniella hepiali A stromata of fungus arising from lepidopteran pupa B stromata and synnemata arising from lepidopteran pupa C, D perithecia E, F asci G colony as obversed on PDA medium H-L conidiophores, phialides and conidia on PDA. Scale bars: 10 mm (A, B); 300 µm (C); 100 µm (D); 20 µm (E, F); 20 mm (G); 10 µm (H, I); 5 µm (J, K).