ASSESSMENT OF RESISTANCE TO THE PATHOGEN OF SOFT ROTAND BLACKLEG COMMON IN UKRAINE POTATO VARIETIES

Abstract

B a c k g r o u n d . The potato crop is affected by various diseases, including blackleg and soft rot caused by Pectobacterium atrosepticum. One of the reasons for the rapid spread of these bacterial pathogens is the absence of commercial potato varieties with natural immunity to blackleg and soft rot. While some potato varieties may exhibit partial resistance, the lack of complete resistance contributes to the widespread occurrence of these diseases. The study aimed to evaluate the resistance of potato varieties most common in Ukraine to blackleg and soft rot pathogens. M e t h o d s . Potato varieties from different region of Ukraine were used in the study. 24 h culture of Pectobacterium atrosepticum B-1084T was used for assessing potato sensitivity to soft rot and blackleg. Potato susceptibility to soft rot pathogen was evaluated by two criteria: disease incidence (%) and disease severity (weight and area of macerated tissue). R e s u l t s . Potato tubers of different varieties, as well as of the same varieties, but grown in different regions of Ukraine, showed different levels of resistance to the museum strain of soft rot and blackleg pathogen. The disease incidence – the proportion of tubers with symptoms of rotting for all analyzed potato varieties reached 100 %.Tubers of the Riviera variety obtained from the Odesa region were significantly more affected by the pectolytic enzymes of P. atrosepticum B-1084T as compared to tubers of other cultivars: macerated area in tubers of this variety was 1.5 times higher than those in Queen Anne, Riviera (Chernihiv) and Bellarosa (Odesa) varieties. The median of maceration area of Picasso and Bellarosa (Chernihiv) tubers were 2.5 times smaller than that in the Riviera variety. These patterns of sensitivity to soft rot and blackleg pathogen were also confirmed by the results of comparative assessment of the weight of. C o n c l u s I o n s . Thus, Riviera potato variety was most susceptible to the infection with soft rot and blackleg pathogen. Potato cultivar Picasso was the least sensitive to P. atrosepticum B-1084T. Potato tubers of the same variety grown in different regions of the country had different susceptibility rates to the soft rot and blackleg pathogen, indicating that the field effect outweighs the influence of genotype.