Scientific Journal of KubSAU

The pathogenic agent of apple scab disease, Venturia inaequalis (Cooke) Winter, causes significant damage to the industrial production of apples. Studying the pathogen in pure culture is important for solving the theoretical and practical issues of its biology. The sporulation ability of the Venturia inaequalis laboratory culture is an important diagnostic feature in morphological culture analysis, in the test for sensitivity to fungicides, when creating a collection inoculum for an artificial infection. We have studied the morphological features of conidiogenesis of pure V. inaequalis culture, such as the location of conidiogenic structures and their form. For the first time in the laboratory culture of the pathogen, sporulation in the thickness of agar on the substrate mycelium was demonstrated. Conidiogenesis proceeded according to the blastic-annellidic type. Depending on the location of the conidiogenic structures on the aerial or substrate mycelium, their morphology was different. Conidiogenic areas in the substrate mycelium could be observed with the unaided eye, in the form of hyphal grit, while they were conidia conglomerations in each annelid. Annellide had a curved shape. On the aerial mycelium, annelids were straight and always had only one conidium. Differences in the morphology of conidiogenic structures are supposed to be related to the physical conditions of the environment in which sporulation takes place. In the agar, each mature conidium remaining at the apex of the annelid interferes with the formation of the next one, which results in its bending. The fixed arrangement of conidiogenic structures and forming conidia in the thickness of agar allows the use of substrate sporification for model studies of the conidiogenesis process