Diversity and Patulin Production of Penicillium spp. Associated with Apple Blue Mold in Serbia

Apple blue mold, caused by the <i>Penicillium</i> species, is a significant postharvest disease, leading to food loss and impacting food safety due to mycotoxin contamination. This study aimed to identify the <i>Penicillium</i> species associated with apple blue mold in Serbia, assess their pathogenicity, and evaluate their patulin production potential. A total of 70 <i>Penicillium</i> isolates were collected from symptomatic apple fruit and identified as <i>P. expansum</i> (92.9%), <i>P. crustosum</i> (4.3%), <i>P. solitum</i> (1.4%), and <i>P. chrysogenum</i> (1.4%). The pathogenicity assay revealed <i>P. expansum</i> strains as the most virulent. Molecular detection of <i>msas</i> gene and HPLC analysis confirmed patulin production exclusively in <i>P. expansum</i> isolates. Principal Component Analysis (PCA) grouped <i>P. expansum</i> strains in two distinctive clusters, while <i>P. crustosum</i> strains clustered separately with <i>P. solitum</i> and <i>P. chrysogenum</i>, yet in distinct positions. This is the first report of <i>P. solitum</i> and <i>P. chrysogenum</i> as causal agents of apple blue mold in Serbia. The results of the study provide insights that might be useful in the development of effective control strategies for apple blue mold, ensuring consumption of healthy and safe apple fruit and apple-based products.