Aspergillus flavus is known for producing aflatoxins (AFs), which are harmful mycotoxins that can spoil food crops and represent significant health risks to animals and humans. The aim of this study was to analyze fifty samples of livestock and poultry feed to identify mycotoxigenic fungi at both morphological and molecular levels, focusing on their toxigenic potential and genetic diversity. Out of the samples tested, six were confirmed as Aspergillus flavus using internal transcribed spacer (ITS) specific primers, accounting for approximately 12 % of the total detected microorganisms. Morphological and molecular analyses revealed that all strains exhibited 97-100 % similarity with a reference strain and were significant producers of B-type AFs. The data showed that all samples except one (S1) contained total aflatoxin levels below 20 μg/ kg, considered safe for animal consumption according to the European Union (EU), United States Food and Drug Administration (US FDA), and World Health Organization (WHO) guidelines. To assess the genetic variability among A. flavus strains, twelve inter simple sequence repeats (ISSR) primers and seven Sequence Related Amplified Polymorphism (SRAP) primer combinations were utilized, producing scorable and reproducible banding patterns with about 52 % polymorphism. Various genetic diversity parameters, including polymorphic information content (PIC), effective multiplex ratio (EMR), marker index (MI), and resolving power (RP) were evaluated to determine effectiveness of the primers in distinguishing the genetic variations among the A. flavus strains. As particularly valuable markers, the results indicated that ISSR-13, SRAP-1, and SRAP-6 exhibited higher PIC, RP, and MI values, thereby proving to be more informative for identifying the genetic variants.

Potato virus Y (PVY) is a major plant pathogen affecting solanaceous crops, particularly potato and tomato, leading to significant economic losses. The viral coat protein (CP) is essential for virion stability, host interactions, and immune recognition. Identifying conserved and variable epitopes within the PVY CP provides insights into viral evolution, host adaptation, and potential targets for disease control. This study aimed to investigate the conservation and sequence variability of key PVY CP epitopes across diverse geographic locations and host species. By analyzing the epitope sequences, this study identified the conserved regions suitable for diagnostic tools and the variations indicative of viral adaptation. A comparative sequence analysis of PVY strains from different regions was conducted. Multiple sequence alignments determined identity percentages, conserved motifs, and variations in epitopes, including PVY-CP-A, -D, -F, -G, -H, and -I. Most epitopes exhibited high conservation. PVY-CP-A showed 100 % identity in most strains, with slight variations (91.67 %) in a Greek isolate. PVY-CP-D and -F were largely conserved, with minor variations (87.50 %) recorded in Poland and Bangladesh. PVY-CP-G displayed reduced identity (83.33%) in Poland, China, and Bangladesh, suggesting adaptation. PVY-CP-H was completely conserved, reinforcing its structural importance. PVY-CP-I showed the highest conservation, with minor variations in the UK and China. These findings highlight the conserved PVY epitopes as potential targets for universal diagnostic tools and control strategies. Minor variations suggest regional adaptations, influencing pathogenicity, and host interactions. This study provides valuable insights into PVY evolution, aiding in improved virus detection and diagnosis development.