The potato dry rot causal agent and severity in Ardabil storages and the resistance of cultivars to the disease

Dry rot is one of the most important diseases of potato in storages. The aim of this study was to determine dry rot severity in potato storages of Ardabil, identify the disease causal agents and evaluate some potato cultivars resistance to the disease.
Totally 150 infected samples were collected from thirty nine studied storages in Ardabil. Dry rot severity and the prevalence of infected tubers were determined by surveying three 50 kg bags of potato in the storages. Fungi isolated and purified from the tubers with dry rot symptoms. A factorial design with four replications was applied in order to evaluate the reaction of five potato cultivars to four Fusarium species and determining the resistant one to dry rot. Potato tuber slices were inoculated by conidial suspension of Fusarium species. Four days after inoculation and maintaining in darkness and 25oC, the cultivars susceptibility was identified.
Four species of Fusarium were identified as dry rot causal agents in Ardabil as follows: F. oxysporum, F. poae, F. solani and F. sporotrichioides. There was no significant difference between Fusarium species in pathogenicity. The reaction of cultivars to various Fusarium species was different. Boren had the lowest infection (12.5%) and Sabalan showed the highest (98.87 %). Sabalan ،Khavaran ،Agria and hybrid line 3970093 displayed the highest susceptibility to various studied Fusarium species.
Discussion and Based on the results, Boren is introduced as the most resistant cultivar to Fusarium dry rot and Sabalan, Agria and hybrid line 3970093 as the susceptible ones.