Discovery of a new species of the Hypoxylon rubiginosum complex from Iran and antagonistic activities of Hypoxylon spp. against the Ash Dieback pathogen, Hymenoscyphus fraxineus, in dual culture Author Pourmoghaddam, Mohammad Javad Department of Plant Protection, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran & Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030, Wien, Austria & Helmholtz-Zentrum fuer Infektionsforschung GmbH, Dept. Microbial Drugs, Inhoffenstrasse 7, 38124, Braunschweig, Germany Author Lambert, Christopher Helmholtz-Zentrum fuer Infektionsforschung GmbH, Dept. Microbial Drugs, Inhoffenstrasse 7, 38124, Braunschweig, Germany Author Surup, Frank Helmholtz-Zentrum fuer Infektionsforschung GmbH, Dept. Microbial Drugs, Inhoffenstrasse 7, 38124, Braunschweig, Germany Author Khodaparast, Seyed Akbar Department of Plant Protection, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran Author Krisai-Greilhuber, Irmgard Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030, Wien, Austria Author Voglmayr, Hermann Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030, Wien, Austria & Institute of Forest Entomology, Forest Pathology and Forest Protection, Department of Forest and Soil Sciences, BOKU-University of Natural Resources and Life Sciences, Franz-Schwackhoefer-Haus, Peter-Jordan-Strasse 82 / I, 1190, Vienna, Austria https://orcid.org/0000-0001-7666-993X Author Stadler, Marc Helmholtz-Zentrum fuer Infektionsforschung GmbH, Dept. Microbial Drugs, Inhoffenstrasse 7, 38124, Braunschweig, Germany https://orcid.org/0000-0002-7284-8671 marc.stadler@t-online.de text MycoKeys 2020 66 105 133 http://dx.doi.org/10.3897/mycokeys.66.50946 journal article http://dx.doi.org/10.3897/mycokeys.66.50946 1314-4049-66-105 C5A0C9E410E354A8A1FF1A8FE8F4EA98 Hypoxylon rubiginosum (Pers.) Fr., Summa Veg. Scand. II, p. 384. (1849). Fig. 3 Teleomorph. Stromata superficial, effused-pulvinate, up to 8 cm long x 0.3-0.2 cm wide; with inconspicuous to conspicuous perithecial mounds, surface Red (2) to Brick (59); Scarlet (5) to Orange (7) granules beneath the surface and between the perithecia, with Orange (7) to Scarlet (5) KOH-extractable pigments. Perithecia spherical to obovoid, 0.2-0.5 high x 0.15-0.45 mm wide. Ostioles umbilicate, inconspicuous. Asci 8-spored, cylindrical, with amyloid, discoid apical apparatus, 0.5-1 µm high x 1.5-2.5 µm wide, stipe up to 180 µm long and spore-bearing portion 40-80 x 6.5-10 µm . Ascospores smooth, unicellular, brown to dark brown, ellipsoid, inequilateral with narrowly rounded ends, 9-12 (-13) x 4-6 µm , with straight germ slit spore-length on convex side; perispore dehiscent in 10% KOH; epispore smooth. Cultures and anamorph. Colonies on OA covering a 9 cm Petri dish in 3 wk, at first white, becoming Smoke Grey (105), felty, azonate with diffuse margins; finally becoming Pale Luteous (11) to Straw (46). Asexual morph not produced in culture. Secondary metabolites. Rubiginosin A and an unknown compound of the mitorubrin / rubiginosin azaphilone family prevalent; cultures produce phomopsidin and unidentified compounds on barley-malt agar. Specimens examined. Iran, Guilan Province, Siahkal County, Deilaman forest, 36°57'25"N , 49°51'54"E , 1100 m elev., on fallen branch of Quercus castaneifolia , 6 Oct 2017 (GUM 1586; culture MUCL 57727); Guilan Province, Shaft County, 36°59'08"N , 49°18'43"E , 594 m elev., on fallen trunk of Pterocarya fraxinifolia , 15 Sep 2015 (GUM 1583); Guilan Province, Langaroud County, Liseroud forest, 37°7'44"N , 50°8'41"E , 28 m elev., on fallen branch of Quercus castaneifolia , 10 Sep 2016 (GUM 1584); Guilan Province, Talesh County, Gisoum forest, 37°37'30"N , 48°58'15"E , 477 m elev., on fallen branch of Populus sp., 20 Oct 2016 (GUM 1585). All specimens collected by M.J. Pourmoghaddam. Notes. H. rubiginosum sensu stricto is a very common fungus in the temperate Northern hemisphere ( Stadler et al. 2008 ) and may occur in subtropical areas, such as Florida, USA ( Ju and Rogers 1996 ). Most of the characters of the Iranian specimens are in accordance with previous descriptions ( Stadler et al. 2004 ), aside from insignificant variations in the size of ascospores. Figure 3. Hypoxylon rubiginosum (GUM 1586) A, B stromatal habit C close-up view of stromatal surface D close-up view of stromatal surface, with stromatal pigments in 10% KOH E ascospores in 10% KOH with dehiscent perispore F mature and immature asci in water G immature ascus in water H mature ascus in water I ascus in Melzer's reagent J ascospores in water K ascus tip in Melzer's reagent. Scale bars: 2 cm ( A ); 1 cm ( B ); 4 mm ( C ); 2 mm ( D ); 10 µm ( E ); 20 µm ( F-I ), 10 µm ( J, K ).