Aspergillus section Flavi has become focal point of research globally owing to its increasing toxigenicity in food along with wider application in industry. Whereas, identification of species within section Flavi remains challenging due to high level of erraticism in morphological as well as genetic characters therefore, the purpose of this study was to apply polyphasic approach using morphology, extrolite and genetics to characterize Aspergillus isolates in section Flavi. Isolations from different sources lead to morphological characterization of nineteen strains. Identified species were A. flavus, A. flavus var. columnaris, A. oryzae, A. oryzae var. pseudoflavus A. oryzae var. tenuis A. oryzae var. effusus, A. oryzae var. microspores, A. minisclerotigenes and A. parvisclerotigenus. Assessments regarding mycotoxigenic assays through Thin Layer Chromatography (TLC) revealed presence of aflatoxins in thirteen isolates. Amplification of ITS1-5.8S rDNA-ITS2 region produced a PCR product of about 550-650 bp for all strains. BLAST results using ITS sequence of all identified strains showed 100% identity with the many of their respective strains deposited to GenBank. The amplification profiles of ISSR using the P1 (AGAG)4G, P2 (GTG)5, P3 (GACA)4G primers showed an average of 9, 12 and 12 polymorphic bands for the nineteen isolates with band size ranging from 200-1800, 200-1500 and 300-3000bp, respectively. On the basis of amplification banding of ISSR, all isolates were clustered into three clades. A. Present study concludes that proper identification using polyphasic approach is indeed prerequisite that will contribute information in stable taxonomy and nomenclature of A. flavus group.
Full conference title:
- MS 2016