Improving ITS sequence data for identification of plant pathogenic fungi

Plant pathogenic fungi are a large and diverse assemblage of eukaryotes with substantial impacts on natural ecosystems and human endeavours.These taxa often have complex and poorly understood life cycles,lack observable,discriminatory morphological characters,and may not be amenable to in vitro culturing.As a result,species identification is frequently difficult.Molecular(DNA sequence)data have emerged as crucial information for the taxonomic identification of plant pathogenic fungi,with the nuclear ribosomal internal transcribed spacer(ITS)region being the most popular marker.However,international nucleotide sequence databases are accumulating numerous sequences of compromised or low-resolution taxonomic annotations and substandard technical quality,making their use in the molecular identification of plant pathogenic fungi problematic.Here we report on a concerted effort to identify high-quality reference sequences for various plant pathogenic fungi and to re-annotate incorrectly or insufficiently annotated public ITS sequences from these fungal lineages.A third objective was to enrich the sequences with geographical and ecological metadata.The results-a total of 31,954 changes-are incorporated in and made available through the UNITE database for molecular identification of fungi(http://unite.ut.ee),including standalone FASTA files of sequence data for local BLAST searches,use in the next-generation sequencing analysis platforms QIIME and mothur,and related applications.The present initiative is just a beginning to cover the wide spectrum of plant pathogenic fungi,and we invite all researchers with pertinent expertise to join the annotation effort.

One stop shop:backbones trees for important phytopathogenic genera:Ⅰ(2014)

Many fungi are pathogenic on plants and cause significant damage in agriculture and forestry.They are also part of the natural ecosystem and may play a role in regulating plant numbers/density.Morphological identification and analysis of plant pathogenic fungi,while important,is often hampered by the scarcity of discriminatory taxonomic characters and the endophytic or inconspicuous nature of these fungi.Molecular(DNA sequence)data for plant pathogenic fungi have emerged as key information for diagnostic and classification studies,although hampered in part by non-standard laboratory practices and analytical methods.To facilitate current and future research,this study provides phylogenetic synopses for 25 groups of plant pathogenic fungi in the Ascomycota,Basidiomycota,Mucormycotina(Fungi),and Oomycota,using recent molecular data,up-to-date names,and the latest taxonomic insights.Lineagespecific laboratory protocols together with advice on their application,as well as general observations,are also provided.We hope to maintain updated backbone trees of these fungal lineages over time and to publish them jointly as new data emerge.Researchers of plant pathogenic fungi not covered by the present study are invited to join this future effort.Bipolaris,Botryosphaeriaceae,Botryosphaeria,Botrytis,Choanephora,Colletotrichum,Curvularia,Diaporthe,Diplodia,Dothiorella,Fusarium,Gilbertella,Lasiodiplodia,Mucor,Neofusicoccum,Pestalotiopsis,Phyllosticta,Phytophthora,Puccinia,Pyrenophora,Pythium,Rhizopus,Stagonosporopsis,Ustilago and Verticillium are dealt with in this paper.