Morphological and Molecular Characterization of Apple Scab (Venturia inaequalis) in Kazakhstan and Kyrgyzstan

Apple scab, caused by the fungus <i>Venturia inaequalis</i>, is one of the most widespread and economically significant diseases of apple orchards, leading to reduced photosynthesis, fruit damage, and yield losses of up to 70%. In this study, a survey of 30 wild and cultivated apple populations in Kazakhstan and Kyrgyzstan was conducted, encompassing 302 samples. The pathogen was detected in 8 populations (48 samples), corresponding to an infection rate of 16%. Molecular identification using the <i>EF-1α</i> marker and ITS region sequencing definitively confirmed the presence of <i>V. inaequalis</i> in all positive samples. Phylogenetic analysis showed clear population structuring: isolates from Kyrgyzstan formed a distinct clade close to international lineages, while Kazakh isolates showed high genetic variation. These findings highlight the ongoing presence of <i>V. inaequalis</i> in Central Asia and emphasize the importance of combining morphological, molecular, and phylogenetic methods for effective pathogen monitoring and control.