Of the Temperate and Subtropical Northern Hemisphere
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North American Fungi Volume 3, Number 7, Pages 73-125 Published August 29, 2008 Formerly Pacific Northwest Fungi The "red Hypoxylons" of the temperate and subtropical Northern hemisphere Marc Stadler1,2, Jacques Fournier3, Alfred Granmo4 and Esperanza Beltrán-Tejera5 1University of Bayreuth, Dept. Mycology, Universitätstraße 30, D-95447 Bayreuth, Germany; 2InterMed Discovery GmbH, Otto-Hahn-Strasse 15, D-44227 Dortmund, Germany; 3Las Muros, F-09420, Rimont, France; 4Department of Natural Science, Tromsø University Museum, University of Tromsø, NO–9037 Tromsø, Norway; and 5Departamento de Biología Vegetal (Botánica), Universidad de La Laguna, 38071 La Laguna, Tenerife, Canary Islands, Spain. Stadler, M. J. Fournier, A. Granmo, and E. Beltrán-Tejera. 2008. North American Fungi 3(7): 73-125. doi:10.2509/naf2008.003.0075 Corresponding author: Marc Stadler; [email protected]. Accepted for publication December 11, 2007. http://pnwfungi.org Copyright © 2008 Pacific Northwest Fungi Project. All rights reserved. Abstract: Selected taxa of Hypoxylon from the Northern hemisphere were compared with numerous type and authentic specimens of H. fuscum, H. rubiginosum, and presumably related taxa. Besides morphological analyses, we used secondary metabolite profiles based on high performance liquid chromatography, coupled with diode array detection and mass spectrometry (HPLC-DAD/MS). Chemotaxonomic studies on the Nitschke and Persoon types of the above names and further ancient type specimens turned out to be rather conclusive. Along with the information provided in the world monograph of Hypoxylon by Ju and Rogers, the results of our HPLC profiling studies are regarded as key asset to provide a better overview on the diversity and biogeography of these species complexes. The utility of this approach is demonstrated by a study on Hypoxylon in the Canary Islands. From a 74 Stadler et al. “Red Hypoxylon” species of the Northern Hemisphere. North American Fungi 3(7): 73-125 comparison of morphological and chemical traits with the above mentioned material, we recognize two new species (H. canariense and H. urriesii). The predominantly tropical H. anthochroum and H. subrutilum were also found from this archipelago, but representatives of these taxa from different parts of the world showed heterogeneous HPLC profiles. The number of accepted species in Hypoxylon might increase substantially, once an inventory of their tropical representatives, based on holomorphic morphology and considering the importance of their stromatal extrolites, has been completed. Key words: Biogeography, chemotaxonomy, evolution, fungal pigments, Xylariaceae, Xylariales. Introduction: The monograph of the late diagnostic tool to identify Hypoxylon species. Julian H. Miller on Hypoxylon (Miller 1961) was Numerous new species were recognized from this instrumental, because his taxonomic concepts approach, and subsequent additions. Ju et al. provided the basis for modern taxonomy of the (2004) provided an update on the taxonomy of hypoxyloid Xylariaceae. From several thousands the genus, listing all additional taxa that were of specimens, Miller (1961) evaluated the published since 1996. morphology of the teleomorph, emphasizing features such as stromatal morphology and color, In addition, high performance liquid ostioles, and the size of asci and ascospores. chromatography (HPLC) and other methods of Continuous studies of this fungal group revealed analytical chemistry were carried out in other characters such as shape and dehiscence of conjunction with the methods deemed perispores, morphology of germ slits, spore diagnostically helpful by Ju and Rogers (1996). surface structures (as assessed by light This resulted in the identification of various microscopy and scanning electron microscopy), stromatal pigments that are common in and stromatal pigments to be useful for species Hypoxylon and allies, or even specific for certain discrimination. Several of his broad species groups as seen for taxa in the H. rubiginosum concepts were meanwhile further resolved, and complex (Stadler et al. 2004a, Hellwig et al. the genus rearranged (Hsieh et al. 2005; Ju et al. 2005). Several of these metabolites were isolated 1998, 2002; Læssøe et al. 1989; Pouzar 1979, to purity and identified by spectral methods. 1985a, 1985b; Rogers and Ju 1998). Pioneering Standards of the pure compounds now facilitate studies on anamorphs of Hypoxylon sensu lato their detection in crude extracts of other were performed by, e.g., Greenhalgh and specimens. The distribution of stromatal pigment Chesters (1968), Jong and Rogers (1972), Petrini classes (Quang et al. 2005a, Stadler and Fournier and Müller (1986), and van der Gucht (1995). Ju 2006b) in Annulohypoxylon (Hsieh et al. 2005; and Rogers (1996) provided for the first time a Ju and Rogers 1996 as Hypoxylon sect. comprehensive revision of this genus, based on Annulata, resp.) agreed also well with holomorphic morphology. They traced and morphological data . Even in an ancient studied numerous type specimens, and ultimately specimen, such as the type specimen of Sphaeria provided a “List of Names” that is most helpful to cohaerens Pers. (Quang et al. 2005a), stromata everybody who wishes to study xylariaceous taxa of Daldinia Ces. & De Not. (Stadler et al. 2001), in future. For the first time they studied and several other genera of Xylariaceae stromatal pigments of a representative number of (Entonaema A. Möller, Phylacia Lev., specimens including all available type material. Rhopalostroma D. L. Hawksw., Sarcoxylon In 10% potassium hydroxide (KOH) soluble Cooke, and Thamnomyces Ehrenb.; see Stadler et stromatal pigments are now a standard al. 2004c) chemotypes as revealed by HPLC Stadler et al. “Red Hypoxylon” species of the Northern Hemisphere. North American Fungi 3(7): 73-125 75 profiling proved to be consistent in recently purple pigments, many of them former synonyms collected material and old herbarium specimens, of H. rubiginosum or H. fuscum (Miller 1961), even if the latter had been collected over 200 from the temperate and subtropical Northern years previously. If deviations in the chemotypes hemisphere, aimed to establish further were observed, those were frequently also correlations between morphological and chemo- accompanied by deviating morphological taxonomic traits. An overview is provided here. characters. As an exception, some species may show a successive production of different The above mentioned method also proved useful metabolite family during stromatal ontogeny to study Hypoxylon in the Canary Islands (IC – (Stadler et al. 2006a). However, even such Islas Canarias). The biota of these islands were metabolite profiles appear to be quite species- not affected by the Quaternary ice ages. They consistent and only dependent on the stage of have been isolated from the large continents stromatal development in a given species, rather since the opening of the Atlantic ocean between than on external, environmental factors, and Africa and America in the mid-Tertiary. Besides extremely consistent in fully mature material the contributions to the Ascomycetes in the IC by (i.e., the type specimens!). The above results the mycological department of the University of demonstrated the utility of chemotaxonomic La Laguna (Beltrán-Tejera and Wildpret 1975; methods to revise herbarium specimens, not only Bañares Baudet et al. 1986; Beltrán-Tejera et al. in Xylariaceae. 1987; Bañares Baudet et al. 1987; Beltrán-Tejera et al. 1989; Bañares Baudet et al. 1991; Beltrán- Nonetheless, in the holomorphic species concept Tejera et al. 2003; Beltrán Tejera et al. 2004; applied by Ju and Rogers (1996), it is important Beltrán-Tejera et al. 2008, in press), the most to study also material that can be cultured and exhaustive studies on macaronesic discomycetes examined for anamorphic traits. In fact, Ju and have been made by Richard P. Korf and his Rogers (1996) described the majority of the collaborators (Korf 1978; 1981 a,b,c; 1992; Korf cultured specimens from fresh material collected et al. 1978; Ouelette and Korf 1979; Greenleaf and in Mexico, Taiwan, and the USA. However, the Korf 1980; Dissing and Korf 1980; Korf and types of many names in Hypoxylon were Zhuang 1991 a, b, c, d, e, f, g; Iturriaga 1995; frequently collected from other geographic Iturriaga and Korf 1997, 1998; Lizon et al. 1998; regions than the cultured material studied in the etc.). These publications included several latter monograph. Except for some of the most taxonomic revisions and even a large number of common species, a few cultures of Hypoxylon taxa new to Science. More recently, new species that were identified according to the modern have been described for Hyphodiscus (Galán and taxonomy are available in public collections. Raitviir 2004), and Orbilia (Baral and Marson in Corresponding herbarium material of strains Karasch et al. 2005), and some records of new deposited earlier on in these collections is often species of anamorphic fungi (Castañeda Ruiz et missing. Moreover, most herbarium specimens al. 1996, 1997). In fact, IC and other Maca- of Hypoxylon have never been revised using the ronesian islands (Azores, Madeira, Cabo Verde) modern taxonomic concept. Examples are H. are well-known to harbor a large number of anthochroum Berk. & Broome and H. fusco- endemic plants (Francisco-Ortega et al. 2000). purpureum (Schwein. : Fr.) Fr., which were At the present time there are around 320 treated as synonyms of H. rubiginosum by Miller catalogued species of Ascomycota