پراکنش ویروس وای سیب‌زمینی (Potato Y virus) در نواحی کشت توتون استان گلستان

More than 50% of the tobacco cultivation area of Iran is concentrated in Golestan province and the highest levels of cultivation belonging to Virginia (61%) and Basma (31%). Potato Y virus, is the type member of the genus Potyvirus, family Potyviridae, is the most destructive virus of tobacco worldwide. Host range of PVY is widespread and infects more than nine plant families. In tobacco, PVY modifies the chemical composition of cured leaves, especially the nicotine content, resulting in high economic losses. PVY is one of the most common viruses in tobacco fields of Golestan, Mazandaran and Gilan provinces. In order to PVY detection and determination of virus distribution in Golestan province, several surveys were conducted during July- October 2017 at 15 days intervals in tobacco fields of Gorgan, Aliabad and Minoodasht. A total of 3690 leaf samples were randomly collected from symptomatic and symptomless tobacco plants and then all were subjected for double antibody sandwich-ELISA (DAS-ELISA) using PVY-specific polyclonal antibodies to estimate changes in the incidence of PVY infection. Fluctuation of PVY infection rate during four months period was usually sinusoidal and the maximum and minimum infection rates differed between cities. Based on the results, 426 out of 3690 samples (11.5%) were PVY infected. The rate of PVY infection in Virginia, Basma and Barley was estimated as 55%, 29% and 16%, respectively. Based on the tobacco cultivation area, the rate of infection in Gorgan, Aliabad and Minoodasht was estimated as 41%, 35% and 24%, respectively. Maximal and minimal rate of PVY infection was determined in tobacco fields of Taqartappeh (belongs to Gorgan with 32%) and Pichak mahalleh (belongs to Aliabad with 4%).