Diplodia mutila (Fr.) Mont., Ann. Sci. nat., ser . 2, 1: 302. 1834.

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

Diplodia mutila (Fr.) Mont., Ann. Sci. nat., ser. 2, 1: 302. 1834.

Fig. 9

Sphaeria mutila Fr., Syst. Mycol. (Lundae) 2: 424. 1823. Basionym.

Physalospora mutila ≡ Physalospora mutila (Fr.) N.E. Stevens, Mycologia 28: 333. 1936.

Botryosphaeria stevensii = Botryosphaeria stevensii Shoemaker, Canad. J. Bot. 42: 1299. 1964.

Description.

Saprobic on decaying branches of Camellia oleifera . Sexual morph: Not observed. Asexual morph: Coelomycetous, Conidiomata 330-394 × 215-230 μm (x̄ = 362 × 223 μm, n = 10), immersed, erumpent, gregarious, dark brown to black, subglobose, unilocular. Ostiole 48.5-67 μm diam., central. Peridium 29-38 μm wide, thick-walled, outer and inner layers composed of 1-2 layers dark brown textura angularis, intermediate layers composed of 3-5 layers of hyaline cells of textura angularis. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 8.5-12 × 3-5 μm (x̄ = 10 × 4 μm, n = 20), cylindrical, thin-walled, hyaline, holoblastic, indeterminate, proliferating at the same level to produce periclinal thickenings, or proliferating percurrently giving rise to 2-3 indistinct annellations. Conidia 19-21 × 9.5-11 μm (x̄ = 20 × 10.5 μm, n = 30), L/W ratio = 2, oblong, with broadly rounded apex and truncate base, thick-walled, wall externally smooth, roughened on the inner surface, hyaline, aseptate, becoming dark brown when aged.

Culture characteristics.

Colonies on PDA initially olivaceous buff in the center of the colony and white at the edge, becoming olivaceous within 7 d on the surface, with smooth edge.

Materials examined.

China, Sichuan Province, Jiangyou City , Shuanghe County, 31°54'10"N, 104°55'57"E, elevation 657 m, on dead branches of Camellia oleifera , 11th July 2021, W.L Li, 286 (HUEST 22.0069), living culture UESTCC 22.0068 ; ibid., 289 (HUEST 22.0068), living culture UESTCC 22.0067 ; ibid., Guangyuan city, Qingchuan County, 32°40'38"N, 105°28'57"E, elevation 634 m, on dead branches of Olea europaea , 20th April 2021, W.L Li, 188 (HUEST 22.0065), living culture UESTCC 22.0064 ; ibid., 257 (HUEST 22.0070), living culture UESTCC 22.0069 ; ibid., on dead branches of Vernicia fordii , 20th April 2021, W.L Li, 238 (HUEST 22.0066), living culture UESTCC 22.0065 ; ibid., Chengdu City, Pidu District , 30°49'27"N, 103°47'42"E, elevation 442 m, on dead branches of Pistacia chinensis , 5th March 2021, W.L Li, A61 (HUEST 22.0064), living culture UESTCC 22.0063. Additional sequences: LSU: OQ164832 (UESTCC 22.0063), OQ164830 (UESTCC 22.0064), OQ164831 (UESTCC 22.0065) .

Notes.

The phylogenetic tree show that six strains isolated from Camellia oleifera , Olea europaea and Vernicia fordii nested with Diplodia mutila (CBS 112553) with a moderate bootstrap support (ML/BI 86%/1). Diplodia mutila , the type of the genus, is a well-known and most commonly reported species. It has been recorded mainly from woody substrates, and it is known from more than 50 hosts ( Batista et al. 2021). Morphologically, one of the isolates obtained in this study UESTCC 22.0068 shares similar conidia shape and size with Di. mutila , but hardly observed the mature conidia with septa. We identify these taxa as Di. mutila based on morphology and phylogeny evidences. This is the first report of Di. mutila , isolated from Camellia oleifera , Olea europaea and Vernicia fordii .

Figures

Figure 9. Diplodia mutila (HUEST 22.0069, new host record) a, b appearance of conidiomata on natural substrate c vertical section of conidioma d ostiole e section of peridium f-i conidiogenous cells and developing conidia j hyaline immature conidium k-n mature brown conidia. Scale bars: 40 μm (c); 20 μm (d, e); 10 μm (f-n).