Persoonia 33, 2014: 61–82 www.ingentaconnect.com/content/nhn/pimj RESEARCH ARTICLE http://dx.doi.org/10.3767/003158514X684212 Stilbosporaceae resurrected: generic reclassification and speciation H. Voglmayr1, W.M. Jaklitsch1 Key words Abstract Following the abolishment of dual nomenclature, Stilbospora is recognised as having priority over Prosthecium. The type species of Stilbospora, S. macrosperma, is the correct name for P. ellipsosporum, the type Alnecium species of Prosthecium. The closely related genus Stegonsporium is maintained as distinct from Stilbospora based Calospora on molecular phylogeny, morphology and host range. Stilbospora longicornuta and S. orientalis are described as Calosporella new species from Carpinus betulus and C. orientalis, respectively. They differ from the closely related Stilbospora ITS macrosperma, which also occurs on Carpinus, by longer, tapering gelatinous ascospore appendages and by dis- LSU tinct LSU, ITS rDNA, rpb2 and tef1 sequences. The asexual morphs of Stilbospora macrosperma, S. longicornuta molecular phylogeny and S. orientalis are morphologically indistinguishable; the connection to their sexual morphs is demonstrated by Phaeodiaporthe morphology and DNA sequences of single spore cultures derived from both ascospores and conidia. Both morphs rpb2 of the three Stilbospora species on Carpinus are described and illustrated. Other species previously recognised in systematics Prosthecium, specifically P. acerophilum, P. galeatum and P. opalus, are determined to belong to and are formally tef1 transferred to Stegonsporium. Isolates previously recognised as Stegonsporium pyriforme (syn. Prosthecium pyri­ forme) are determined to consist of three phylogenetically distinct lineages by rpb2 and tef1 sequence data, two of which are described as new species (S. protopyriforme, S. pseudopyriforme). Stegonsporium pyriforme is lectotypified and this species and Stilbospora macrosperma are epitypified. Based on DNA sequence data, the North American Stegonsporium acerophilum is recorded from Europe for the first time, and new hosts from Acer sect. Acer are reported for S. opalus and S. pyriforme. Stilbospora and Stegonsporium are classified within the revived family Stilbosporaceae. Prosthecium appendiculatum, P. auctum and P. innesii are shown to be unrelated to the Stilbo­ sporaceae and are recognised in three distinct genera, Phaeodiaporthe appendiculata, Alnecium auctum n. gen. and Calosporella innesii within Diaporthaceae, Gnomoniaceae and Sydowiellaceae, respectively. The generic types of these three monotypic genera are briefly described, illustrated and lecto- and epitypfied. Article info Received: 26 August 2013; Accepted: 5 March 2014; Published: 18 August 2014. INTRODUCTION host specific, being mostly confined to a single host species. In addition, two distinct species of Prosthecium having Stegon­ Wehmeyer (1941) gave an account of the diaporthalean genus sporium asexual morphs were each found to co-occur on the Prosthecium Fresen. 1862, basically characterised by incon- European Acer pseudoplatanus and on the North American spicuous or light-coloured ectostromatic discs, scant prosen- Acer saccharum. All hosts of the maple-inhabiting species were chymatous entostroma and large, several-celled, appendaged revealed to belong to Acer section Acer. ascospores and several-celled conidia, with two subgenera. Recent changes of the International Code of Nomenclature Later Barr (1978) separated species of the subgenus Pseudo­ (ICN) for unified nomenclature raised the question of appro- prosthecium, distinguished by elongate ascospore append- priate generic classification of the species currently classified ages, as Hapalocystis Auersw. ex Fuckel (see also Jaklitsch & within Prosthecium. Stilbospora macrosperma Pers., the type Voglmayr 2004). While the asexual genus Stilbospora had been species of Stilbospora Pers. 1801, was confirmed as the asex- widely regarded as being linked to Prosthecium (Winter 1887, ual morph of Prosthecium ellipsosporum, the generic type of Petrak 1923, Barr 1978), the genus Stegonsporium was long Prosthecium, by Voglmayr & Jaklitsch (2008), thus these genera thought to be the asexual morph of the pleosporalean genus are synonyms. Because the genus Stilbospora Pers. (Persoon Splanchnonema (Kirk et al. 2001). However, Voglmayr & Jak- 1801) is older than Prosthecium, the use of Prosthecium would litsch (2008) confirmed Stilbospora macrosperma Pers. as the require conservation (Crous et al. 2012). As the asexual morph asexual morph of Prosthecium ellipsosporum, and they clearly placed in Stilbospora is more common and conspicuous than showed that also Stegonsporium belongs to Prosthecium. the sexual morph, it seems practical to follow the principle of In their account of Prosthecium, Voglmayr & Jaklitsch (2008) priority and recognise Stilbospora over Prosthecium. re-defined the genus Prosthecium, confining it to parasites Stilbospora and Stegonsporium are closely related genera of Carpinus with Stilbospora asexual morphs and Acer with both of which have sexual morphs that have been placed in Stegonsporium asexual morphs, respectively. They docu- Prosthecium (Voglmayr & Jaklitsch 2008). Both share similar mented Prosthecium ellipsosporum from Carpinus betulus, acervular conidiomata with simple, hyaline paraphyses and and described five species of Prosthecium with Stegonsporium hyaline, cylindrical, septate conidiophores, annellidic conidio- asexual morphs from Acer, concluding that they were highly genous cells and brown, septate conidia with a hyaline sheath. Stilbospora is characterised by ellipsoid to oblong euseptate 1 Division of Systematic and Evolutionary Botany, Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030 Wien, ascospores and conidia with usually three transverse eusepta, Austria; corresponding author e-mail: [email protected]. whereas Stegonsporium has mostly pyriform conidia with 2–7 © 2014 Naturalis Biodiversity Center & Centraalbureau voor Schimmelcultures You are free to share - to copy, distribute and transmit the work, under the following conditions: Attribution: You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work). Non-commercial: You may not use this work for commercial purposes. No derivative works: You may not alter, transform, or build upon this work. For any reuse or distribution, you must make clear to others the license terms of this work, which can be found at http://creativecommons.org/licenses/by-nc-nd/3.0/legalcode. Any of the above conditions can be waived if you get permission from the copyright holder. Nothing in this license impairs or restricts the author’s moral rights. 62 Table 1 Hosts, origin, herbarium, culture and GenBank accession numbers of the specimens used for phylogenetic analyses. For details on collection data, see Voglmayr & Jaklitsch (2008) and lists of specimens examined. Taxa, hosts and origins in bold denote new species, hosts and origins, respectively, for the species. Type species marked by an asterisk (*); E = epitype, H = holotype, N = neotype. Taxon Host Origin Voucher, culture number Type GenBank accession no. LSU ITS tef1 rpb2 Alnecium auctum* Alnus glutinosa Austria WU 30206, PAT = CBS 124263 (ex teleomorph) E KF570154 KF570154 KF570200 KF570170 Phaeodiaporthe appendiculata* Acer campestre Austria WU32448, D76 = CBS 123809 (ex teleomorph) KF570155 KF570155 Acer campestre Austria WU32449, D77 = CBS 123821 (ex teleomorph) E (Diaporthe appendiculata, KF570156 KF570156 Phaeodiaporthe keissleri) Stegonsporium acerinum Acer saccharum Canada WU 28047, D43 = CBS 120525 (ex teleomorph) E EU039996 EU039968 EU040024 Acer saccharum Canada WU 28047, D42 = CBS 120524 (ex anamorph) E EU039995 EU039969 EU040023 KF570171 S. acerophilum Acer grandidentatum UK, England WU 32468, D65 = CBS 125042 (ex anamorph) KF570202 KF570174 Acer saccharum Canada WU 28048, D44 = CBS 120602 (ex teleomorph) EU039981 EU040029 Acer saccharum Canada WU 28049, D45 = CBS 120601 (ex anamorph) EU040030 KF570172 Acer saccharum Czech Republic WU 32465, D81 = CBS 125028 (ex anamorph) KF570157 KF570157 KF570203 Acer saccharum UK, England WU 32467, D64 = CBS 125033 (ex anamorph) KF570201 Acer saccharum USA WU 28050, D5 = CBS 117025 (ex teleomorph) E EU039993 EU039982 EU040027 KF570173 Acer saccharum USA WU 28050, D6 = CBS 117026 (ex anamorph) E EU039994 EU039985 EU040028 Acer saccharum USA WU 28051, D23 = CBS 117035 (ex anamorph) EU039984 EU040026 Acer saccharum USA WU 28052, D24 = CBS 117036 (ex anamorph) EU039983 EU040025 S. galeatum Acer heldreichii UK, Scotland WU 32469, D70 = CBS 125035 (ex anamorph) KF570204 KF570176 Acer pseudoplatanus Austria WU 28055, D38 = CBS 119744 (ex anamorph) EU040012 Acer pseudoplatanus Austria WU 28056, D41 = CBS 120523 (ex teleomorph) E EU040013 KF570175 Acer pseudoplatanus Austria WU 28057, D1 (culture lost) (ex teleomorph) EU039988 EU039966 EU040014 Acer pseudoplatanus Austria WU 28058, D3 = CBS 117024 (ex teleomorph) EU039989 EU039967 EU040011 S. opalus Acer hyrcanum Austria WU 32783, D59 = CBS 124485 (ex anamorph) KF570205 Acer monspessulanum France WU 32470, PR15 (ex anamorph) KF935260 KF570210 KF935261 Acer obtusatum Austria WU 28059, D40 = CBS 120603 (ex anamorph) EU039990 EU040018 KF570177 Acer obtusatum Croatia WU 28060, D52 = CBS 121690 (ex teleomorph) EU040022 KF570179 Acer obtusatum Italy WU 28061, D51 = CBS 121691 (ex teleomorph) EU040021 Acer obtusatum Slovenia