Sphaeropsis citrigena (A.J.L. Phillips, P.R. Johnst. & Pennycook) A.J.L. Phillips & A. Alves. Stud. Mycol. 76, 157. (2013).

Li, Wen-Li, Liang, Rui-Ru, Dissanayake, Asha J. & Liu, Jian-Kui, 2023, Botryosphaerialean fungi associated with woody oil plants cultivated in Sichuan Province, China, MycoKeys 97, pp. 71-116 : 71

Sphaeropsis citrigena (A.J.L. Phillips, P.R. Johnst. & Pennycook) A.J.L. Phillips & A. Alves. Stud. Mycol. 76, 157. (2013).

Fig. 17

Description.

Saprobic on decaying branches of Camellia oleifera . Sexual morph: Ascomata 219-252 × 216-241 μm (x̄ = 235.5 × 228.5 μm, n = 10), brown to black, solitary or aggregated, immersed, becoming erumpent, ostiolate. Ostiole 71-92 μm, central, relatively broad. Peridium 37.5-45 μm diam., composed of several layers of dark brown cells of textura angularis. Pseudoparaphyses 1.5-2 μm wide, hyaline, smooth, septate. Asci 93.5-107 × 28.5-33 μm (x̄ = 100 × 30.5 μm, n = 30), bitunicate, 8-spored, stipitate, thick-walled, with well-developed apical chamber. Ascospores 29-35 × 13-15 μm (x̄ = 32 × 14 μm, n = 30), L/W ratio = 2.3, yellowish brown to dark brown, ellipsoid to ovoid with both ends rounded, with an apiculus at either end, aseptate, externally smooth, internally finely verruculose, widest in middle to upper third. Asexual morph: Not observed.

Culture characteristics.

Ascospores germinate on PDA within 12 h. Colonies growing on PDA, reaching a diam. of 7 cm after five days at 25 °C, effuse, velvety, with entire to slightly undulate edge. Surface initially white and later turning dark olivaceous from the surrounding of the colony and dark gray in reverse.

Materials examined.

China, Sichuan Province, Chengdu City, Pidu District , 31°54'10"N, 104°55'57"E, 656 m, on dead branches of Camellia oleifera , 10th June 2021, W.L Li, 285 (HUEST 22.0107), living culture UESTCC 22.0106; ibid., on dead branches of Acer truncatum , 30°19'57"N, 103°59'47"E, elevation 442 m, 19th March 2021, W.L Li, A33 (HUEST 22.0106), living culture UESTCC 22.0105. Additional sequence: LSU: OQ164848 (UESTCC 22.0105) .

Notes.

The phylogenetic tree shows that two isolates of Sphaeropsis from our collection clustered together with the ex-type strain of Sp. Sphaeropsis citrigena (ICMP 16812) with high bootstrap support (ML/BI 100%/1). Sphaeropsis citrigena was first described as Phaeobotryosphaeria citrigena by Phillips et al. (2008), later transferred to Sphaeropsis based on morphological and phylogenetic analyses ( Phillips et al. 2013). The new collection (UESTCC 22.0105) isolated from Camellia oleifera resembles Sp. Sphaeropsis citrigena isolated from Citrus sinensis ( Phillips et al. 2013) in the shape of asci and ascospores, though their asci are somewhat smaller than those of Sp. Sphaeropsis citrigena (93.5-107 × 28.5-33 μm vs. 180-230 × 35-43 μm). In addition, there are no base pair differences in ITS and tef1 sequences of these two strains. We, thus, identify the new collection as Sp. Sphaeropsis citrigena and this is the first record of Sp. Sphaeropsis citrigena from Camellia oleifera .

Figures

Figure 17. Sphaeropsis citrigena (HUEST 22.0107, new host record) a, b appearance of ascomata on natural substrate c vertical section of ascomata d section of peridium e-h mature asci i-m dark brown ascospores. Scale bars: 100 μm (c); 20 μm (d-h); 10 μm (i-m).