Taxonomic circumscription and phylogenetics of novel didymellaceous taxa with brown muriform spores

Sexual morph of didymellaceous taxa are characterized by their ascomata with relatively thin peridium,cylindric-clavate to clavate,short-pedicellate or apedicellate asci,hyaline to brown,1-septate to muriform ascospores.Its asexual morphs are coelomycetous and comprising pycnidial or acervulus conidiomata,phialidic,hyaline conidiogenous cells and hyaline or pale brown,septate or aseptate conidia.The majority of these cosmopolitan species are plant associated fungi which can be pathogens on a wide range of hosts and some species are of particular relevance for quarantine measures.Recent studies have significantly improved the taxonomy and systematics of didymellaceous taxa based on molecular phylogenetics.In contrast to the accurate and detailed studies on the asexual morphs which are common obligate pathogens,information on their usually saprobic sexual morphs is still limited.Among these phenotypically diverse species,spore characteristics are quite unique as most have hyaline spores with 0-1 septum,while only Neomicrosphaeropsis and Didymellocamarosporium are reported as producing pigmented,muriform spores.These dematiaceous muriform spores are characteristic of a considerable number of species that may be quite divergent in other characters.During taxonomic investigations on the diversity of didymellaceous taxa,we have isolated species from Alhagi pseudalhagi,Coronilla emerus,Cytisus sp.,Elaeagnus angustifolia and Spartium junceum in Italy,Russia and Uzbekistan.A comprehensive phylogeny,based on four loci(ITS,LSU,rpb2 and tub2)is used to infer species relationships.Comprehensive morphological descriptions and in-depth phylogenetic investigations of five new species viz.Ascochyta coronillae-emeri,Microsphaeropsis spartii-juncei,Neomicrosphaeropsis alhagi-pseudalhagi,N.cytisicola and N.elaeagni are presented.

Transient leaf endophytes are the most active fungi in 1-year-old beech leaf litter

The ecological significance of fungi occurring asymptomatically inside living plant leaves is poorly understood.Given the broad saprotrophic potential of many endophytic fungi,we hypothesized that they persist in decaying litter for an extended period of time after leaf abscission.Fungal assemblages were assessed by highthroughput sequencing in autumn leaves of beech(Fagus sylvatica)and in the corresponding leaf litter in 388 samples from 22 beech forest plots in three widely distant regions of Germany.A considerable proportion of the leafendophytic fungi was also found in 1-year-old litter.Cooccurrence networks revealed that the fungi formed unstructured assemblages inside the living leaves,rather than well-structured communities.Previously endophytic fungi constituted an integral part of the fungal litter community and were by far the most active fungi in 1-year-old litter.We therefore consider these endophytic occurrences to represent transient stages.Composition of the aboveground microbiome appears therefore to be closely connected to the process of litter decomposition.Considering the respective linked fungal habitat will facilitate predicting nutrient and carbon cycling and storage in forest ecosystems as well as elucidating the ecology of leaf microbiomes.