Dothiorella viticola A.J.L. Phillips & J. Luque

Rathnayaka, Achala R., Chethana, K. W. Thilini, Phillips, Alan J. L. & Jones, E. B. Gareth, 2022, Two new species of Botryosphaeriaceae (Botryosphaeriales) and new host / geographical records, Phytotaxa 564 (1), pp. 8-38 : 22

Dothiorella viticola A.J.L. Phillips & J. Luque , Mycologia 97(5): 1118 (2005)

Index Fungorum number: IF 357425; Facesoffungi number: FoF11671, Fig. 8

Saprobic on branch of Morus sp. Sexual morph: see Luque et al. (2005). Asexual morph: Coelomycetous. Conidiomata 125–135 μm high × 105–120 μm diam. (x̄ = 130 × 110 μm, n = 10), pycnidial, solitary or gregarious, globose to subglobose, uniloculate, immersed, becoming erumpent at maturity. Ostiole single, central, circular, papillate. Conidiomata wall 10–30 μm diam., composed of thin-walled, brown cells of textura angularis, inner layer thin, hyaline. Conidiophores usually reduced to conidiogenous cells. Conidiogenous cells 6–12 × 2–5 μm (x̄ = 8 × 3 μm, n = 15), lining the pycnidial cavity, holoblastic, hyaline, cylindrical, discrete, determinate, smooth-walled. Conidia 16–22 × 8–12 μm (x̄ = 19 × 10 μm, n = 30), oblong to ovoid, straight, rounded at both ends, initially hyaline and aseptate, becoming brown and 1-septate often while attached to conidiogenous cells, slightly constricted at the septum.

Culture characteristics:— Conidia germinating on PDA within 24 h. Germ tubes produced from one side of the conidium. Colonies on PDA reaching 2.0– 2.5 cm diam. after 5 days at 16 °C, circular, medium dense, flat or effuse, slightly raised, fluffy to fairly fluffy, grey colour in front and black in reverse.

Material examined:— ITALY. Viale Salinatore - Forlì (province of Forlì-Cesena [FC]): on dead branch of Morus sp. (Moraceae) , 3 February 2019, Erio Camporesi, (MFLU 19-0621, new host record), living culture MFLUCC 22- 0059.

Known hosts and distribution:— Dothiorella viticola has a cosmopolitan distribution in different host species, including Citrus sp. in the USA ( Adesemoye & Eskalen 2011, Inderbitzin et al. 2010), Populus cathayana in China ( Zhang et al. 2009), Poniciana gilliesii in France ( Phillips et al. 2008), Prunus persica and P. salicina in South Africa ( Damm et al. 2007), and Vitis vinifera in Australia, South Africa and Spain ( Luque et al. 2005, de Wet et al. 2009, Qiu et al. 2011).

Notes:—Our collection is similar to the holotype of Dothiorella viticola (MFLU 18–1586) from pruned canes of Vitis vinifera in Spain (CBS 117009) ( Luque et al. 2005). Both isolates have similar morphology, with separate or aggregated, erumpent, globose, uniloculate conidiomata, and a single, central, circular, and papillate ostiole. They have holoblastic and hyaline conidiogenous cells. Their conidia are oblong, initially hyaline and aseptate that become pigmented brown, 1-septate and slightly constricted at the septum. However, the width of conidiomata (x̄ = 110 μm) and length/width (L/W) ratio of conidia of our new collection (L/W = 1.9) are comparatively smaller than the ex-type strain (x̄ = 295 μm and L/W = 2.2 ± 0.02) ( Luque et al. 2005). Based on phylogenetic analyses, our collection clustered with other strains of D. viticola (IRNBS28, WA10NO01 and WA10NO02) with relatively high 93% ML bootstrap and 0.93 PP support ( Fig. 1 ). Based on the morpho-molecular evidence, we identified our collection as a new host record of D. viticola on Morus sp. in Italy.

Figures

FIGURE 1. Phylogram generated from ML analysis based on combined dataset of ITS, LSU, tef1-α and β-tub. The tree is rooted to Neofusicoccum luteum (CMW 4165 and CBS 562.26). Tree topology is similar to the previous study by Zhang et al. (2021). Bootstrap support values for ML ≥ 70% and Bayesian posterior probabilities (PP) ≥ 0.90 are noted at the nodes. Strain numbers are noted after the species names. Strains isolated in this study are presented in red and type strains are in bold.