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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Mycotoxin Prevention and Applied Microbiology Research » Research » Publications at this Location » Publication #335773

Research Project: Genomic Analyses and Management of Agricultural and Industrial Microbial Genetic Resources and Associated Information

Location: Mycotoxin Prevention and Applied Microbiology Research

Title: Phylogeny of xerophilic aspergilli (subgenus Aspergillus ) and taxonomic revision of section Restricti

item SKLENAR, FRANTISEK - Charles University, Czech Republic
item JURJEVIC, ZELJKO - Emsl Analytical, Inc
item ZALAR, POLONA - University Of Ljubljana
item VISAGIE, COBUS - University Of Ottawa
item KOLARIK, MIROSLAV - Charles University, Czech Republic
item HOUBRAKEN, JOS - Fungal Biodiversity
item CHEN, AMANDA - Fungal Biodiversity
item YILMAZ, NERIMAN - Eastern Cereals & Oilseed Center
item COTON, MONICA - Technopole De Brest-Iroise
item DENIEL, FRANCK - Technopole De Brest-Iroise
item Peterson, Stephen

Submitted to: Studies in Mycology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/21/2017
Publication Date: 9/30/2017
Citation: Sklenar, F., Jurjevic, Z., Zalar, P., Frisvad, J.C., Visagie, C.M., Kolarik, M., Houbraken, J., Chen, A.J., Yilmaz, N., Seifert, K.A., Coton, M., Deniel, F., Peterson, S.W. et al. 2017. Phylogeny of xerophilic aspergilli (subgenus Aspergillus ) and taxonomic revision of section Restricti. Studies in Mycology. 88:161-236. doi: 10.1016/j.simyco.2017.09.002.

Interpretive Summary: A group of molds that specializes in rotting of low water content commodities such as stored grains was re-examined using molecular techniques. We found that in addition to the seven easily identified species, there are 14 undescribed species in this group. We devised a way to identify all of the new molds. This work will be of interest to plant pathologists, industries providing mold identification services, and academic mycologists.

Technical Abstract: Aspergillus section Restricti together with sister section Aspergillus (formerly Eurotium) comprises xerophilic species, that are able to grow on substrates with low water activity and in extreme environments. We adressed the monophyly of both sections within subgenus Aspergillus and applied a multidisciplinary approach for definition of species boundaries in sect. Restricti. The monophyly of sections Aspergillus and Restricti was tested on a set of 102 isolates comprising all currently accepted species and was strongly supported by Maximum likelihood (ML) and Bayesian inferrence (BI) analysis based on ß-tubulin (benA), calmodulin (CaM) and RNA polymerase II second largest subunit (RPB2) loci. More than 300 strains belonging to sect. Restricti from various isolation sources and four continents were characterized by DNA sequencing, and 193 isolates were selected for phylogenetic analyses and phenotypic studies. Species delimitation methods based on multispecies coalescent model were employed on DNA sequences from four loci, i.e., ID region of rDNA (ITS + 28S), CaM, benA and RPB2, and supported recognition of 21 species, including 14 new. All these species were also strongly supported in ML and BI analyses. All recognised species can be reliably identified by all four examined genetic loci. Phenotype analysis was performed to support the delimitation of new species and includes colony characteristics on seven cultivation media incubated at several temperatures, growth on an osmotic gradient (six media with NaCl concentration from 0 to 25 %) and analysis of morphology including scanning electron microscopy. The micromorphology of conidial heads, vesicle dimensions, temperature profiles and growth parameters in osmotic gradient were useful criteria for species identification. The vast majority of species in sect. Restricti produce asperglaucide, asperphenamate or both in contrast to species in sect. Aspergillus. Mycophenolic acid was detected for the first time in at least six members of the section. The ascomata of A. halophilicus do not contain auroglaucin, epiheveadride or flavoglaucin which are common in sect. Aspergillus, but shares the echinulins with sect. Aspergillus.