Alternaria italica J.F. LI, Camporesi & K.D. Hyde, Mycosphere 9(1): 43 (2018)

Index Fungorum number: IF553987; MycoBank number: MB553987; Facesoffungi number: FoF 03880

Parasitic on living leaves, causing leaf spots of J. regia. Sexual morph: Undetermined. Asexual morph: Conidiophores 40–290 × 4–7 µm (x̄ = 118 × 5 µm, n = 20), macronematous, mononematous, light brown to brown, thick-walled, smooth, septate, partly branched, straight or flexuous, cylindrical. Conidiogenous cells 14–21 × 9–15 µm (x̄ = 17 × 12 µm, n = 20), cicatrized, monoblastic, integrated, terminal, determinate or percurrent, cylindrical, doliiform, subhyaline, smooth, thin-walled. Conidia 42–98 × 13–19 µm (x̄ = 69 × 15 µm, n = 40), acrogenous, holoblastic, solitary, light grey to brownish grey, 5–9-septate or more, dry, simple, straight, curved, fusiform, obpyriform, obturbinate or subglobose, catenate, sometimes rostrate, smooth, thin-walled.

Cultural characteristics – Conidia germinating on PDA within 24 hours and germ tubes produced from all cells. Colonies growing on PDA, hairy or cottony, brown to dark brown, reaching 60 mm in 20 days at 25ºC, mycelium superficial, effuse, radially striate, with irregular edge, brown to dark brown hyphae, there are flocculent grey white aerial hyphae in the center. reverse, grey at the margin, light brown to grey in the center.

Material examined – China, Wenchuan, Sichuan, (31°20′21′′N, 103°28′40′′E), dead leaves of Juglans regia (Juglandaceae), 7 July 2022, FeiHu Wang, WFH202207016 (SICAU 23-0071), living culture (SICAUCC 23-0050).

GenBank numbers – ITS: PP060666, LSU: PP057958, rpb2: PP061119 and tef1-ɑ: PP061144

Notes: Alternaria italica is a pathogen in plants due to its causing leaf blights. Based on morphology, Jayawardena et al. (2018) and Liao et al. (2023) reported this species from Italy and China. In this study, we identified this species as a pathogen of Juglans regia based on morphology as well as sequence data.

Fig. 1 – Alternaria italica (SICAU 23-0071). A. Appearance of colonies in host substrate. B. Colonies on substrate. C-E Conidiophores connected to conidia. F chain conidia. G-I Conidia J. Germinated conidia. K, L Colonies on PDA. Scale bar: B = 500 μm, C-F = 50 μm, G-J = 20 μm.