Isolation and Molecular Analysis of Aspergillus spp. Associated with Melon Seeds

Abstract

Seed-borne fungi are a big menace to agriculture and food safety in that they decrease seed viability, favor spoilage and may even induce mycotoxin into the food chain. The purpose of the research was to isolate and molecularly characterize Aspergillus species related to melons ( Cucumis melo ) seeds sampled in Penjwen. Isolation was done through the agar plating method on potato dextrose agar (PDA) and morphologically identified. Six Aspergillus species were obtained: A. flavus, A. niger, A. corrugatus, A. fumigatus, A. terreus and A. tamarii, with A. flavus having the highest prevalence (30%). The polymerase chain reaction (PCR) amplification of internal transcribed spacer (ITS1/ITS4), large subunit ribosomal RNA (LSU) and b-tubulin (Bt2a/Bt2b) gene segments were used to determine molecular identification. Fragmentary products of anticipated sizes, namely 650 bp (ITS), 1200 bp (LSU) and 495 bp (b-tubulin) were visualized and verified through agarose gel electrophoresis. Species identity and evolutionary relationship of the isolates were further confirmed by sequencing and phylogenetic studies. The prevalence of A. flavus and other species of Aspergillus highlights their ability to adapt to dry seed conditions and possible ability to generate spoilage-related enzymes and secondary metabolites. These results demonstrate the necessity of introducing appropriate seed management and storage to prevent fungal contamination and guarantee the quality of seeds.