Investigation on the response of Iranian oriental and semi oriental tobacco genotypes to Potato Virus Y under controlled conditions

Potato virus Y (PVY) as one of the serious diseases on tobacco (Nicotiana tabacum L.), reduces leaf yield and its quality. Use of resistant genotypes is being considered as the most effective, economical and a safe way to reduce damages of the virus. In the present study, the response of 90 oriental and semioriental tobacco genotypes was evaluated against PVY using randomized complete block design with three replications under controlled conditions. Each replicate consisted of 6 seedlings. The leaves of each genotype were inoculated mechanically via rubbing method at 4-6 leaf stage with PVY. Four weeks following inoculation, the studied genotypes showed different severity symptoms associated with PVY. ELISA assay were applied on the inoculated plants by the indirect method using the polyc lonal antibody specific to PVY. Optical density value of each infected sample was read at 405 nm using an ELISA reader. Analysis of variance on ELISA data showed significant differences among genotypes for concentration of PVY. Results revealed that 'Erzeogovina' genotype with OD=0.68881 contained the highest virus concentration whereas the 'KB101' genotype with OD=0.0005 contained the lowest virus concentration. The differed reactions of genotypes to PVY virus encourage the use of resistance genetic resource for the reduction of disease damages.