Dothiorella sarmentorum (Fr.) A.J.L. Phillips, A. Alves & 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 : 19

Dothiorella sarmentorum (Fr.) A.J.L. Phillips, A. Alves & J. Luque , Mycologia 97(2): 522 (2005)

Index Fungorum number: IF 501403; Facesoffungi number: FoF02148; Fig. 7

Saprobic on twig of Humulus lupulus . Sexual morph: See Phillips et al. (2013) Asexual morph: Coelomycetous. Conidiomata 70–105 μm high × 16–30 μm diam. (x̄ = 76 × 19 μm, n = 10), pycnidial, solitary or gregarious, globose to subglobose, formed in uniloculate stromata, immersed, becoming erumpent at maturity. Conidiomata wall 1.9–3.8 μm diam. composed of thin-walled, brown cells of textura angularis, inner layer thin, hyaline. Conidiophores usually reduced to conidiogenous cells. Conidiogenous cells 11–18 × 3–5μm (x̄ = 14.5 × 4.4 μm, n = 15), lining the pycnidial cavity, holoblastic, hyaline, cylindrical, discrete, determinate, smooth-walled. Conidia 25–31 × 10–15 μm (x̄ = 28 × 12.4 μm, n = 20), 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 upper side and black on the lower side.

Material examined:— ITALY. Collina di Forlì (province of Forlì-Cesena [FC]): on dead branch of Humulus lupulus (Cannabaceae) , 8 January 2019, Erio Camporesi, (MFLU 19-0437, new host record), living culture MFLUCC 22- 0060.

Known hosts and distribution:— Dothiorella sarmentorum has a cosmopolitan distribution and has been isolated from 34 different host species, including Malus , Menispermum , Prunus , Pyrus , Ulmus , etc. ( Phillips et al. 2013). However, Dissanayake et al. (2016) mentioned that D. sarmentorum was described from only 17 woody hosts based on molecular studies.

Notes:—The morphology of the specimen from this study is similar to the holotype of Dothiorella sarmentorum collected from Menispermum canadense in Sweden ( Phillips et al. 2013). Both specimens have many similar characteristics with solitary and globose conidiomata, a conidiomata wall composed of brown to hyaline cells of textura angularis, conidiogenous cells that are holoblastic and hyaline, and conidia that are initially hyaline and aseptate, becoming brown and 1-septate often while attached to conidiogenous cells, with a similar L/W ratio (2.2) ( Phillips et al. 2013). Based on phylogenetic analyses, our strain (MFLUCC 22-0060) clustered with the ex-type and other isolates of D. sarmentorum (CBS 115041, CBS 128309, CBS 141587, CBS 392.80, CBS 725.79, IMI 63581b, IRAN 1579C, IRAN 1583C, MFLUCC 13-0498, MFLUCC 17-0242 and MFLUCC 17-0951) with relatively high 99% ML bootstrap and 1.00 PP support ( Fig. 1 ). Previously, D. sarmentorum has been recorded from Italy on different hosts ( Dissanayake et al. 2016). Considering the morpho-molecular data analysis, we conclude that our new collection is a new host record of D. sarmentorum 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.

FIGURE 7. Dothiorella sarmentorum on dead branch of Humulus lupulus (MFLU 19-0437). a, b. Conidiomata on branches of Humulus lupulus. c. Vertical section through conidioma. d. Peridium of conidioma. e–g. Conidia attached to conidiogenous cells. h, i. Conidia. j. Germinating conidium. l, m. Colony on PDA (l upper, m lower). Scale bars: a, b = 200 μm, c = 100 μm, d–j = 20 μm.