Plectosphaerella melonis (Syn. Acremonium cucurbitacearum) — Plant Pathogenic Organism

Fungal diseases cause signifi cant damage to agriculture. Plectosphaerella melonis (syn. Acremonium cucurbitacearum and Nodulisporium melonis) is a pathogen of cultivated plant diseases in Spain, Italy, Japan, USA, Egypt, and Ukraine. This review discusses the main results of research related to this phytopathogen. By morphological and cultural features, P. melonis is a morphologically intermediate species between A. strictum and A. charticola, however, 5.8S-ITS regionbased phylogenetic analysis showed that P. melonis is a monophyletic taxon more closely related to Plectosphaerella than to other species of the genus Acremonium. The most susceptible plants are at the stage of germination; however, the development of the disease is manifested in the fruiting period. For a comprehensive assessment of virulence, real leaf area (RLA) of the first two leaves, lesion of hypocotyl (RH), root collar (RSR), primary (R1R) and secondary roots (R2R) are measured. P. melonis affects the root system, in particular the root collar and hypocotyl, and colonizes the epidermis and cortex of the root centrographically towards the stem. The range of host plants includes Cucurbitaceae, however, peppers, tomatoes, basil, and parsley are infected as well. Plants vary in susceptibility depending on the species and even variety. The pathogenic response of plants differs depending on the growing conditions (protected and open soil), the interaction between the pathogen and competing microorganisms, and other ecological and trophic relationships. The main means of control are the use of long-term crop rotations and the selection of resistant varieties. In Ukraine, a strain of the antagonist fungus Trichoderma viride was selected, which is an effective means for controlling P. melonis 502. The aim of our work was to establish the role of P. melonis in the development of diseases of cultivated plants.