MULTIGENE SEQUENCE-BASED POLYPHASIC IDENTIFICATION AS A HIGHLY RESOLVING APPROACH IN FUNGAL PHYLOGENY

Recent progressive advances in fungal phylogenyhave introduced many approaches that can challengethe conventional way of classification. The analysisof conserved genes, total and partial secondarymetabolites analysis and cell wall chemotaxonomy areamong the very well-known novel approaches thathave been used for deep classification of various taxa.In this study small subunit (18s) ribosomal RNA gene(SSU) and internal transcribed spacer (ITS) sequencingwas used for identification of 19 ascomycetesbelonging to the various orders of Eurotiomycetesand Dothideomycetes. The identified species belongto penicillium purpurogenum, Penicillium oxalicum,Penicillium chrysogenum, Penicillium roqueforti,Penicillium crustosum, Aspergillus terreus, Aspergillussclerotiorum, Emericellopsis pusila, Phoma leveillei andChaetomium globosum species. Gene bank nucleotidedatabase was used for alignment and tree designingusing Geneious and Mega5packages. It was shown thatthe alignment of SSU sequences is not highly resolvingbecause it is highly conserved in dikarya and the SSUfragment can be recommended only for resolving highertaxa (order to genus). But the ITS sequencing is a verypowerful resolving and statistically proved approach thatin some cases can be used for subspecies determination(genus to subspecies). To design a multigene phylogenyapproach by sequence-based polyphasec identification,AFTOL and Gene bank databases were studied forfinding new conserved fragments and it was decipheredthat together with ITS fragment, the protein coding EF1and RPB2 fragments and specially RPB1 gene as thebest candidates can be used for species determinationand deep taxa identification that can result in noveldata of evolutionary and phylogenic relationships with aconsiderable resolving power

کلیدواژه ها:

Multigene phylogeny ، SSU ، ITS ، AFTOL ، ascomycetous yeasts