Hypomyces ampullaris Jing Z. Sun, 2021

Gu, Xin, Fu, Rong, Wang, Rui & Sun, Jing-Zu, 2021, Two new Hypomyces associated with boletoid fungi in China, Phytotaxa 516 (1), pp. 28-42 : 35-36

Hypomyces ampullaris Jing Z. Sun , sp. nov. FIGURE 2

Index Fungorum number: IF558005

Etymology: — The specific epithet refers to its ampullar conidia.

Type:— CHINA, Sichuan Province, Yancheng city (27°39′31″N, 101°14′16″E), from a fruiting body of Boletus sp. 8 August 2018 ; Fu Rong & Liu Xing-Zhong ( HMAS 291301 , holotype), ex - type living culture CGMCC 3.20157 .

Fungicolous, growing on a fruiting body of Boletaceae sp. Asexual morph: Hyphomycetous. Mycelium forming a loosely attached layer on the fruiting body of the host ( FIGURE 2a ). On PDA medium, colony forming a thick mat, white at the beginning, then becoming yellow ( FIGURE 2b, c ). Mycelium superficial, copious, developing as floccose masses of septate, branched, warted and hyaline hyphae bearing robust conidiophores with white spore masses ( FIGURE 2b ). Conidiophores hyaline, erect, flexuous, branched, septate, warted. With two types of conidiogenous cells phialidic and aleuriogenic ( FIGURE 2d– f, i ). Type A: Phialides in 2–3 verticels, hyaline, warted, 16–40 × 4–5.5 μm (x̅ = 25 × 5 μm, n = 30), attenuating to 1.5–3.0 μm at their apices ( FIGURE 2d, g, h ). Phialoconidia acrogenous, hyaline, ampulliform, aseptate, 12–18 × 5.5–7.5 μm (x̅ = 14.5 × 6.5 μm, n = 50) ( FIGURE 2k–m ). Type B: Aleuriogenic discrete, on short side branches, hyaline, warted ( FIGURE 2e, f, i ). Aleurioconidia hyaline at the beginning, becoming golden yellow when mature, subglobose to globose, thick - walled, aseptate, with angular tubercles on surface, 20–27 × 19–26 μm (x̅ = 23 × 22.5 μm, n = 50) ( FIGURE 2e, f, i, j ). Tubercles, cylindrical, 1–1.5 μm, often with apical depression, densely arranged ( FIGURE 2j ). Sexual morph: Undetermined.

Other material examined:— CHINA, Sichuan Province, Yancheng city (27°39′31″N, 101°14′38″E), from a fruiting body of Boletales sp. 8 Aug 2018; Fu Rong ( YY28-1 ), living culture CGMCC 3.20158 .

Notes:—The new species has grown on fruiting bodies of Boletaceae sp. containing only the asexual state. Among the known Boleticolous species of Hypomyces , H. ampullaris is morphologically similar to Sepedonium ampullosporum Damon in forming candelabrum like conidiophores and producing ampulliform conidia. But S. ampullosporum differs in having longer phialides (30–80 × 3.5 μm) and larger ampulloconidia (14–20 × 6–8 μm), and pigment discoloration of medium ( Damon 1952, Sahr et al. 1999, TABLE 2).

Figures

FIGURE 2. Hypomyces ampullaris (CGMCC 3.20157). a Yellow colony on a fruiting body of Boletus sp. b, c Forward and reverse of a colony on PDA. d–g Conidiophores. h Phialides. i Aleurioconidia on short side branches. j Aleurioconidia. k–m Phialoconidia.Scale bars: d–g = 50 μm, h–i = 25 μm, j–m = 10 μm.