Linteromyces quintiniae Crous, in Crous et. al., Persoonia 45: 287 (2020)

Index Fungorum number: IF 837834; MycoBank number: MB 837834; Facesoffungi number: FoF 15046;

Etymology – Name refers to the host genus Quintinia from which it was isolated.

Asexual morph: Mycelium consisting of hyaline, smooth, branched, septate, 1.5–2 µm diam. hyphae. Conidiophores reduced to conidiogenous cells or subcylindrical, brown, smooth, erect, unbranched, becoming dark brown and thick-walled with age, up to 8-septate and 100 µm tall, 3–4 µm diam., with integrated terminal conidiogenous cells. Conidiogenous cells solitary, erect, integrated on hyphae, pale to medium brown, smooth, doliiform to subcylindrical, 5–20 × 4–6 µm, with several cylindrical denticles near apex, 2–4 × 1–1.5 µm. Conidia solitary, aseptate, medium brown, slightly roughened, fusoid, apex and base with apiculus, 1–2 × 1 µm, guttulate, with paler germ slit along length of conidium body, (16–)20–22(–24) × (6–)7 µm.

Culture characteristics — Colonies erumpent, spreading, surface folded, with moderate aerial mycelium and smooth, lobate margin, reaching 25 mm diam. after 2 weeks at 25 °C. On MEA, surface pale olivaceous grey, reverse olivaceous grey; on PDA, surface pale olivaceous grey, reverse olivaceous grey; on OA, surface dark brick.

Typus – AUSTRALIA, New South Wales, Limpinwood Nature Reserve, Corina Lookout, on leaves of Quintinia sieberi (Paracryphiaceae), 25 May 2015, B.A. Summerell, HPC 2945 (holotype CBS H-24409, culture ex-type CPC 38231 = CBS 146792.

GenBank accession numbers – ITS: MW175342, LSU: MW175382.

Notes — Linteromyces resembles the genus Subramaniomyces, which has aseptate, polyblastic conidia occurring in branched, acropetal chains on mononematous, branched conidiophores occurring along the length of brown setae. It is morphologically distinct, however, in having solitary conidia, being phylogenetically unrelated to Subramaniomyces (S. podocarpi, CBS 143176; Crous et al. 2017a), and being close to Tristratiperidium, which again has conidia with terminal setulae (Daranagama et al. 2016). Based on a megablast search of NCBIs GenBank nucleotide database, the closest hits using the ITS sequence had highest similarity to Tristratiperidium microsporum (strain MFLUCC 15- 0413, GenBank NR_164238.1; Identities = 531/581 (91 %), 13 gaps (2 %)), Kiliophora ubiensis (strain IPBCC 131080, GenBank KF056850.1; Identities = 527/579 (91 %), 14 gaps (2 %)), and Kirstenboschia diospyri (strain CBS 134911, GenBank NR_145171.1; Identities = 505/559 (90 %), 17 gaps (3 %)). Closest hits using the LSU sequence are Xyladictyochaeta lusitanica (strain CPC 32526, GenBank MH107973.1; Identities = 818 /844 (97 %), no gaps), Castanediella tereticornis (strain CBS 145068, GenBank NG_068600.1; Identities = 818 /846 (97 %), one gap (0 %)), and Castanediella cagnizarii (strain CBS 101043, GenBank KP858988.1; Identities = 820 / 849 (97 %), four gaps (0 %)).