Molecular Identification of Aspergillus flavus isolated from some maize (Zea mays L.) varieties across Abuja, Nigeria

Abstract

This study aims at isolating and molecularly characterizing Aspergillus flavus from maize (Zea mays L.) varieties (Samaz 15,20, 37, 52, Oba super 6, 9, 39, 98, and DK 777) obtained across Abuja, Nigeria. Maize varieties were obtained across the district areas of Abuja namely; Kuje, Kwali, Gwagalada, AMAC, Abaji, Bwari and UniAbuja Experimental field. The potato dextrose agar as a medium was used in growing the fungi from the maize varieties seeds for 7 days at 25oC and then sub-cultured to obtain an isolate into potato dextrose broth. The mycelial mass produced was processed to extract its DNA using genomic DNA extraction of Zymo, D6005 for fungi and bacteria. Molecular Identification of the Internal transcribed spacer (ITS) region for each A. flavus isolate was carried out with ITS1 and ITS4 primers. anf18S rRNA gene region was also amplified with ITS5 and ITS4 primers. 2.0% agarose gels were electrophoresed for 30 minutes in 0.5× buffer, Dye and 60 mM EDTA at 80 V. A gel documentation system was used in determining PCR product sizes by evaluating with internal Mol. Wt. Standards of Thermo Scientific GeneRuler 100 bp DNA Ladder. Fifteen (15) of the twenty (20) fungal isolates were found to be positive with PCR amplification of ITS regions and amplicon sizes of 600 base pairs (bp) for A. flavus were obtained. All the twenty isolates have the presence of 18S rRNA 300-400bp. Thirteen of the fungal growth from the fourteen maize varieties obtained across Abuja were identified as A. flavus.