title: Assignment of species rank to six reproductively isolated cryptic species of the Phialocephala fortinii s.1.-Acephala applanata species complex.
abstract: Phialocephala fortinii s.1. and Acephala applanata are the dominant dark septate endophytes (DSE) in roots of many trees and shrubs. Population genetic analysis led to the discovery of morphologically indistinguishable but reproductively isolated cryptic species (CSP) within Phialocephala fortinii s.1. In the present study we show that sequence data of two coding (beta-tubulin and translation elongation factor [EF-lalpha]) and three noncoding DNA loci confirm subdivision of P. fortinii s.1. and allow to differentiate seven CSP of P. fortinii. In addition we show that strains collected throughout Europe can be classified correctly based on these sequence markers. Statistically significant differences in growth response on different media were observed among CSP of P. fortinii and A. applanata. Growth inhibition on MEA amended with 100 mgl(-1) cycloheximide had the strongest differential effect of all physiological traits examined. In contrast exoenzyme production (laccase, proteinase, pectinase, phenol-oxidase, amylase, cytochrome oxidase and tyrosinase) rarely helped to differentiate CSP of P. fortinii. However A. applanata was a strong producer of amylases, laccases and proteinases. Based on these data we propose to assign species rank to six CSP of P. fortinii: P. turiciensis, P. letzii, P. europaea, P. helvetica, P. uotolensis, P. subalpina spp. nov. and P. fortinii s.s.
authors.affiliation: ETH Zurich, Institute of Integrative Biology IBZ, Forest Pathology and Dendrology, CH-8092 Zürich, Switzerland.
authors.forename: Christoph R
authors.initials: CR
authors.lastname: Grünig
authors.forename: Angelo
authors.initials: A
authors.lastname: Duò
authors.forename: Thomas N
authors.initials: TN
authors.lastname: Sieber
authors.forename: Ottmar
authors.initials: O
authors.lastname: Holdenrieder
mesh_terms: D001203:Ascomycota / Q000145:classification* / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D044822:Biodiversity; D003470:Culture Media / Q000737:chemistry; D004271:DNA, Fungal / Q000235:genetics; D004798:Enzymes / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D020648:Peptide Elongation Factor 1 / Q000235:genetics; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology; D012150:Polymorphism, Restriction Fragment Length; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D013172:Spores, Fungal / Q000166:cytology; D014404:Tubulin / Q000235:genetics
chemical_list: D003470:Culture Media; D004271:DNA, Fungal; D004798:Enzymes; D005656:Fungal Proteins; D020648:Peptide Elongation Factor 1; D014404:Tubulin