Chaetomium globosum Kunze

Chaetomium globosum Kunze View in CoL , Mykol. Hefte 1: 16 (1817).

Fig. 19 View Figure 19

Description.

Sexual morph: Ascomata densely distributed on the surface of PDA medium, initially pale yellow, maturing to yellowish-black after 2 weeks, superficial on the medium, globose to ovate, with an apical ostiole, 158–269 × 136–186 µm, surrounded by ascomatal hairs, the ascomatal wall is brownish and composed of textura intricate. Terminal hairs initially pale yellow, turning brownish-yellow with age, base dark brown, apex pale yellowish-brown, sinuous, septate, unbranched, 146–468 µm long, 1.7–3.9 µm wide at the base. Asci fasciculate, clavate, stipitate, hyaline, 8 - spored, evanescent, 25.6–47.2 × 10.3–17.9 µm (av. ± S. D. = 37.5 ± 5.4 × 14.1 ± 2.1). Ascospores ovoid, hyaline when immature, becoming brown at maturity, 8.5–10.7 × 6.4–8.5 µm (av. ± S. D. = 9.6 ± 0.5 × 7.5 ± 0.5). Asexual morph: Not observed.

Cultural characteristics.

Initially, colonies on PDA medium appeared white. After approximately 7 days, they turned pale yellow and began producing golden-brown ascomata from the center. Within 10 days, the ascomata densely covered the entire medium surface. By 14 days, pale orange-yellow exudates were observed. Upon maturation, ascospores were released through the apical ostioles.

Specimens examined.

China • Beijing City, Changping District, Ming Tombs Reservoir , 40°14'47"N, 116°15'54"E ”, on the diseased scale leaves of Platycladus orientalis , 23 February 2025, Z. X. Bi, BJFC -S 2572 , living cultures CFCC 72642 GoogleMaps ; China • Beijing City, Changping District, Mangshan National Forest Park, Ming Tombs , 40°15'36"N, 116°16'40"E, on the diseased scale leaves of P. orientalis , 23 November 2024, Z. X. Bi & W. K. Gao, BJFC -S 2573 , living culture CFCC 72645 GoogleMaps .

Notes.

Chaetomium was introduced by Kunze, with Chaetomium globosum designated as the type species ( Kunze and Schmidt 1817). C. globosum is a widely distributed endophytic fungus, recorded on numerous plants including Actinidia chinensis , Artemisia argyi , Descurainia sophia , Glycine max , Juncus sp. , Oryza sativa , Platycladus orientalis , and Solanum lycopersicum ( Guo 2012; Wang et al. 2016). As a significant resource fungus, it exhibits critical biological functions such as antimicrobial activity, biocontrol potential, and plant growth promotion ( Ye et al. 2013; Zhao et al. 2017; Tian et al. 2022). In this study, two fungal strains isolated from diseased scale leaves of P. orientalis were analyzed. Based on comprehensive phylogenetic and morphological analyses, strains CFCC 72642 and CFCC 72645 were identified as C. globosum .