Diaporthe italiana

Diaporthe italiana Chethana, Camporesi & K.D. Hyde, in Hyde et al., Fungal Diversity: 10.1007/s13225-019-00429-2, [136] (2019)

Index Fungorum number: IF 555376; Facesofungi number: FoF 04934

Etymology: The specific epithet ‘italiana’ was given after the country, where the fungus was collected.

Holotype: MFLU 17-0311.

Saprobic on a dead aerial branch of Morus alba L. Sexual morph: Perithecia 0.2–0.42 mm (x̄ = 0.311 mm, n = 10), solitary, scattered, immersed to semi-immersed, partially erumpent, globose, black, with tapering perithecial necks. Peridium multi-layered, 20 lm wide at the top, 10–12 μm wide insides, outer layer composed of 4–5 layers of thick, brown cells, inner 3–4 layers of hyaline cells of textura angularis, cells towards inner layer lighter. Asci 45–55 × 6–8.5 μm (x̄ = 51 × 7.7 μm, n = 20), 8-spored, unitunicate, sessile, cymbiform to clavate. Ascospores 10.5–13 × 2.7–4.5 μm (x̄ = 12.1 × 3.5 μm, n = 40), overlapping biseriate, hyaline, fusiform to allantoid, slightly curved, 2-celled, widest near the centre, with acute rounded ends, 1-median septate, rarely bi-guttulate, often tetra-guttulate, with larger guttules at centre and the smaller towards the ends, smooth-walled. Asexual morph: not observed.

Culture characteristics: Colonies on the PDA, circular, fluffy, aerial, white mycelium with fimbriate margin, olivaceous to grey olivaceous reverse, relatively slow-growing, reach 3 cm diam. after 7 days at 25 °C.

Material examined: ITALY, Forlı`-Cesena Province, Forlı`, via Friuli, on dead, aerial branch of Morus alba L. (Moraceae), 19 January 2017, Erio Camporesi, IT 3217 (MFLU 17-0311, holotype), ex-type living culture (MFLUCC 18-0090, KUMCC 18-0002); (HKAS 101460, isotype), ex-isotype living culture (MFLUCC 18-0091, KUMCC 18-0003).

GenBank: CAL: MH853690, ITS: MH846237, TEF1-a: MH853686, TUB2: MH853688 (MFLUCC 18–0090); CAL: MH853691, ITS: MH846238, TEF1-a: MH853687, TUB2: MH853689 (MFLUCC 18-0091).

Notes Diaporthe italiana is phylogenetically closely related to D. rudis, but is clearly distinguished based on the morphology and phylogeny. In our phylogenetic analysis of combined ITS, TEF1-a, TUB2, and CAL sequence data of Diaporthe species, our strains (18-0090 and 18-0091) cluster together with the ex-type strain of Diaporthe rudis (AR3422) with relatively high bootstrap and Bayesian probabilities (100% ML/1.00 BYPP). Sequence comparison for ITS region between D. rudis (AR3422) and D. italiana (MFLUCC 18-0091) showed 2.11% base pair differences. Our collection is distinct from D. rudis in having smaller asci (45–55 9 6–8.5 μm), and smaller ascospores (10.5–13 9 2.7–4.5 μm), in contrast to larger asci (53.5–58.5 9 10.6–12 μm), and larger ascospores (12–14.2 9 3.5–3.7 μm) of D. rudis (Udayanga et al. 2014). A Diaporthe species named Diaporthe mori Berl. (Current name Phomopsis moricola (Sacc.) Grove) has been identified from Morus alba and M. nigra (BargagliPetrucci 1915). However, they differ from our species in having smaller, immersed perithecia (0.18–0.2 mm), smaller asci (36–40 9 7 μm), and smaller, bi-guttulate ascospores (7–8 9 3–3.5 μm). Since this species was introduced in 1915, DNA sequences were unavailable in the databases. Therefore, they were not included in the phylogenetic analysis.