Investigation of the possibility of differentiating genotypes of sugar beet in terms of resistance to beet necrotic yellow vein virus based on phenotypic symptoms in greenhouse conditions

In this study, two different methods were used to evaluate the resistance to rhizomania disease in the root and leaf of sugar beet cultivars Sharif, Dorotea, Aria, Sina, Isabella, Pirola, Ludwina and Brigitta under greenhouse condition. The cultivars' seeds were planted in both sterile (to rub-inoculation leaves) and infection soil (to evaluate infected roots). Results of analysis of variance of greenhouse and laboratory data showed a significant difference between cultivars in terms of virus concentration (based on ELISA test) and percentage of seedling root infection among cultivars; so that the susceptible cultivar Sharif with the average contamination (70.59%) had the highest virus concentration (0.93) and on the other hand, the two cultivars Pirola and Isabella with the average contamination (21.47%) had the lowest virus concentration (0.2). Mechanical inoculation of the virus on the leaves of cultivar seedlings (method 2) showed symptoms of chlorosis and necrosis on the leaves of all cultivars in 10 days post inoculation and there was no difference between resistant and susceptible cultivars. Mechanical inoculation of sugar beet leaves resulted in local symptoms independent of genotype, and it was not possible to distinguish susceptible and resistant genotypes. Therefore, the most appropriate method is to determine the concentration of this virus in the plants’ root after two months.