Pathogenicity Evaluation of Fungal Isolates on Crimean Pine (

This study presents data on the evaluation of the pathogenicity of fungal isolates causing damping-off disease in seeds and seedlings of Crimean pine (Pinus nigra subsp. pallasiana) and their identification based on morphological and molecular methods. A total of eight fungal isolates were obtained from diseased seedlings, of which four were selected for further investigation. The results of pathogenicity tests demonstrated differences in virulence among the isolates, with Fusarium brachygibbosum No. 32 and Fusarium proliferatum No. 36 showing the highest pathogenicity at both seed and seedling stages. Koch's postulates were fully satisfied for these isolates. Molecular-genetic analysis based on the TEF-1α gene identified isolate No. 32 as Fusarium brachygibbosum and isolate No. 36 as Fusarium proliferatum. The results indicate that F. brachygibbosum is reported for the first time as a causal agent of damping-off in Crimean pine. In addition, F. proliferatum also exhibited high pathogenic potential. The findings suggest that damping-off disease may be caused by multiple Fusarium species and highlight the importance of accurate pathogen identification and the application of integrated phytosanitary measures for the production of healthy seedlings.