Comparison of rDNA regions (ITS, LSU, and SSU) of some Aspergillus, Penicillium, and Talaromyces spp.

Abstract

Aspergillus, Penicillium, and Talaromyces spp. are commonly found worldwide and include industrially and medicinally important members. These genera are deeply related with life from soil to health hazards via their industrial products, surface proteins, biodiversity, food spoilage, mycotoxins, etc. These three genera progressively encounter important taxonomic revisions, such as the one fungus-one name concept, and various methods are available to establish their evolutionary and phylogenetic relationships. Besides morphological, microscopic, and extrolite analyses, nucleotide sequence analysis is the most preferred method. In particular, rDNA regions, such as the internal transcribed spacer (ITS), large subunit (LSU), and small subunit (SSU), are commonly used for taxonomic and phylogenetic studies. Although the ITS locus is accepted as the barcode gene for fungal identification, it has some limitations. Therefore, the aim of the present study was to compare ITS, LSU, and SSU loci in terms of ease of application, discrimination of species, and phylogeny by using 43 strains belonging to the above-mentioned three genera of fungi. The results indicated that the ITS and LSU loci were the most effective, exhibiting identical topology and species discrimination, while the SSU locus was the least effective, demonstrating lower species discrimination and the worst topology. Furthermore, the long and high-quality ITS, LSU, and SSU sequences obtained in the present study, which belong to the above-mentioned three genera of fungi, have been deposited in the NCBI database.