Investigating the Potato virus Y main disease indicators in tobacco fields of Golestan province

Potato virus Y, is the type member of the genus Potyvirus, family Potyviridae is of the most destructive viruses of tobacco worldwide. In order to detect PVY and its distribution in Golestan province, several surveys were conducted during July to October 2017 at 15 days intervals in tobacco fields of Gorgan, Aliabad and Minoodasht. 50 plant was selected for each farm and various disease indicators and the virus vector (MP and MPN( were evaluated. Double antibody sandwich-ELISA (DAS-ELISA) using PVY-specific polyclonal antibodies was used to estimate changes in the relative concentrations of PVY. The rate of PVY infection was different among tobacco cultivars and the maximum and minimum infection rates were belonged to PVH03 (33.6%) and Barley (6.2%) cultivars respectively. Based on the statistical analysis of data, there was a significant difference for disease indicators and the virus vector on different tobacco cultivars, as Basma and Barley were less susceptible to PVY than Flue-cured cultivars (PVH03, NC100 and K326). Also, the K326 cultivar has the highest Myzus persicae ssp. nicotiana and Myzus persicae populations. There was a direct correlation between DI and OD and relative humidity and rainfall changes so that DI with rainfall changes had the highest Correlation (r = 0.98 and P = 0.004).