Acidiella bohemica gen. et sp. nov. and Acidomyces spp. (Teratosphaeriaceae), the indigenous inhabitants of extremely acidic soils in Europe

Extremely acidic soils(pH<3)harbour mycobiota that are different from less acidic habitats and are dominated by a small number of fungal species.During investigation of the mycobiota of highly acidic soils in the Czech Republic and Iceland,a group of melanised fungal isolates was obtained.Based on phenotype and nuclear ribosomal DNA sequences(ITS region,SSU,LSU),the isolates were accommodated by three phylogenetic lineages within the family Teratosphaeriaceae(Capnodiales,Dothideomycetes).The first lineage is here described as a new acidotolerant genus and species Acidiella bohemica gen.nov.et sp.nov.The most closely related species to this new clade are other extremotolerant fungi isolated from rocks and lichens collected in the Alps and Antarctica as well as leaf-spotting species and opportunistic human pathogens.The isolates belonging to the second and the third lineages were identified as the recently described acidophilic fungi Acidomyces acidophilus and Teratosphaeria acidotherma,respectively.The taxonomic status of both sister species is discussed and the latter species is ascribed here to the genus Acidomyces.

A new endophytic insect-associated Daldinia species, recognised from a comparison of secondary metabolite profiles and molecular phylogeny

Xylariaceous endophytes are commonly encountered in plants,and it has recently been found out that insect vectors play a major role in their life cycle,as well as in the apparent host-specificity of the fungal stromata.In this study,a new insect-associated,endophytic anamorph species of Daldinia is recognised from a comparison of (a)morphological and ecological data;(b)molecular phylogenetic data based on rDNA,alpha-actin and beta-tubulin genes;and (c)secondary metabolite profiles based on high performance liquid chromatography/diode array/mass spectrometry(HPLC-DAD/MS)and gas chromatography/mass spectrometry(GC-MS)in comparison with authentic strains of Daldinia and other Xylariaceae.The new species,Daldinia hawksworthii,is a symbiont of the willow woodwasp,Xiphydria prolongata,which is in turn preferentially associated with Salix.A comparison of HPLCDAD/MS profiles from standardised cultures revealed the presence of a specific compound,which was not encountered in any of the ca.250 Daldinia strains studied for comparison.This compound was isolated after fermentation of the fungus in 10 l scale by preparative chromatography.Structure elucidation by NMR spectroscopy revealed a novel pyrone,for which the name dalsymbiopyrone is proposed.The compound showed weak antimicrobial and cytotoxic effects and might be a signal molecule involved in the trilateral ecological interaction between the host plant,the insect,and its fungal symbiont.

Diversity of foliar endophytes in wind-fallen Picea abies trees

The unmanaged Norway spruce montane forests in the Bohemian Forest National Park(Czech Republic)suffered from repeated large-scale bark beetle outbreaks in last decade.In this study,the diversity of culturable foliar endophyte microfungi in needles originating from eleven recently wind-fallen trees in this area was surveyed.Our aims were to describe their diversity and to determine the relative host and organ specificities of isolated endophyte species to estimate the species pool and abundance of foliar endophytes before the forest degradation.Microfungi were isolated from surface-sterilized needles,and the outgrowing strains were identified based on morphological and molecular characteristics(analyses of ITS1,ITS2 and partial 28S rDNA).Fungal communities in the needles were diverse,with ascomycetes(mostly anamorphs of Helotiales)dominating basidiomycetes.The most frequent species(Phacidiopycnis sp.,Cistella acuum,Sirococcus sp.and two species of Chalara)did not correspond with those recorded in previous studies of Picea spp.For example,the widely distributed Lophodermium piceae was rarely recorded in this study.This pattern may be caused by different methods of sterilization and cultivation or by physiological characteristics of the needles,or it may reflect the species distribution in the studied area.Members of the Helotiales,along with sequences from GenBank,showed substantial overlap in host affinities,most prominently between Pinus and Picea,and also among species from distant plant lineages.