Pyrenophora verruculosa Madrid, Cantillo & R. Castillo, sp. nov. (Fig. 8)

MycoBank number: MB 551456; Index Fungorum number: IF 551456; Facesoffungi number: FoF 10420;

Etymology: The name refers to the verruculose conidia produced by this species.

Holotype: SGO 168420

     Vegetative hyphae septate, branched, light olivaceous to mid olivaceous brown, thin to thick-walled, smooth, 2–6 µm wide, anastomosing, occasionally showing deposits of a mucilaginous dark brown material. Sexual morph: Undetermined. Asexual morph: Conidiophores macronematous, mononematous, solitary, septate, simple, slightly flexuous to strongly geniculate, light olivaceous brown to dark brown, often paler at the apex, smooth to verruculose, with cell walls often thicker than those of the supporting vegetative hyphae, 300–1270 × 5–9 µm with subnodulose to nodulose intercalary swellings up to 11 µm wide. Conidiogenous cells integrated, terminal and intercalary, mostly subcylindrical, mono- to polytretic, proliferating sympodially, 15–28 µm long. Conidia narrowly clavate, narrowly ellipsoidal to fusiform or subcylindrical, straight to slightly curved, light olivaceous brown to dark brown, verruculose, (26–)32–63(–74) × 12–21 µm, 3–5(mostly 4)-distoseptate, often constricted at the uppermost distoseptum, with a rounded apex and an obconically truncate or rounded base, basal cell sometimes delimited by a thick, dark septum. Hilum thick and dark. Microsclerotia abundant, mostly 45–240 µm wide.

Material examined: CHILE, El Loa Province, Atacama Desert, near Calama, isolated from unidentified Poaceae, 15 October 2015, H. Madrid & L. Linaje (SGO 168420, holotype), ex-type living culture HM 201.

     Notes: DNA sequence analyses revealed that Pyrenophora verruculosa is clearly distinct from all other members of Pyrenophora represented in GenBank. The closest hits in BLAST searches with the ITS sequence of strain HM 201 were Pyrenophora novozelandica (CBS 127934) (ex-type, GenBank MK539997, 96.55% similarity), P. fugax (CBS 509.77) (GenBank MK539985, 95.23% similarity), P. nisikadoi (CBS 190.29) (ex-type, as “Bipolaris brizae”, GenBank MH855213, 93.57% similarity), and P. nobleae (CBS 259.80) (GenBank MK539994, 91.33% similarity). BLAST searches with the GPDH sequence showed that P. fugax (CBS 509.77) (GenBank AY004822, 95.70% similarity) and P. nobleae (CBS 966.87) (GenBank AY004824, 88.81% similarity) as the closest matches. These close relatives can be distinguished easily from P. verruculosa on the basis of conidial dimensions, i.e. smaller in P. novozelandica (20.5–58 × 9.5–14 µm) and P. nisikadoi (15–42.5 × 8.5–12 µm) and longer in P. fugax (50–170 × 14–24 µm) and P. nobleae (55–125 × 9–19 µm) (Sivanesan 1987, Marin-Felix et al. 2019).