Incidence of Tomato Double Streak Virus in Varamin Region

Varamin with the area of over 3000 hectares of tomato plantations is accounted for one of the most important tomato producer region in Iran. During the years 2007 to 2009, a survey was conducted through different tomato fields in Varamin region. A viral disease like symptom of stem necrosis streaks and necrotic spots on fruits were recorded on some tomato plants. Biological properties of suspected viral agents by inoculation to indicator herbaceous plants were studied. Symptomatic tomato leaf, stem and fruit samples were collected and serologically tested by DAS-ELISA and NCM-ELISA methods for the presence of ToMV, TMV and PVX viruses using polyclonal antibodies (Agdia, Inc, U.S.A) (DSMZ, Inc,Germany). TMV was largely detected in all tested indicator plants by NCM-ELISA method. According to the results obtained by DAS-ELISA ToMV, TMV and PVX viruses were detected alone or in mixed infection in the tomato plants showing stem necrotic streak symptoms. Double and triple infections involving different combinations of viruses were found in were observed on 20 and 5/3 % of samples, respectively. Symptoms appeared on inoculated indicator plants were in concordance with what had been reported before for the assayed viruses two weeks after virus inoculation. Symptomatic indicators leaves were serologically tested by NCM-ELISA method for the presence of TMV by means of DSMZ commercial polyclonal antibody (DSMZ,Inc,Germany).Using RT-PCR molecular method and specific primers designed for the coat protein gene, presence of the TMV, ToMV and PVX confirmed for the ELISA positive tested tomato plants. All tested samples were amplified 694bp, 686 and 714 bp fragments for TMV, ToMV and PVX tested samples, respectively. Detection of TMV, ToMV and PVX in doubly infection in samples shows the evidence of Tomato double streak virus in surveyed region. This is the first report of tomato infecting double streak virus disease in Iran, Tehran province.