An Overview of Major Penicillium Species Associated with Plant Diseases

Species of Penicillium are among the most important fungal pathogens responsible for postharvest diseases of agricultural crops worldwide. This review provides an overview of five economically important Penicillium spp., namely P. expansum, P. digitatum, P. italicum, P. citrinum, and P. oxalicum. Emphasis is placed on P. expansum, P. digitatum, and P. italicum which are the main causal agents of blue mold and green mold rots in pome fruits and citrus, commodities that dominate global fresh produce trade and long-term storage. While studies on plant-pathogenic Penicillium are mainly focused on these hosts, this review highlights reports of infections in other crops across diverse geographic regions, highlighting the broader host range of these species. The main aspects highlighted include host specificity and diversity, production of mycotoxins and other secondary metabolites, current management and control strategies, and the potential influence of climate change on disease incidence and severity. Understanding the biology and epidemiology of plant-pathogenic Penicillium species is essential, as several species are both pathogens and producers of mycotoxins, leading to quality deterioration and nutrient depletion resulting in economic losses.