Serological and molecular detection of Tomato spotted wilt virus on some weed reserviors of saffron fields in South Khorasan.

Saffron is one of the most important crop in agriculture and export in Iran and identification of its reduced agents are important. Tomato spotted wilt virus is one of the destructive viruses. Weeds are reservoir plants of viruses. In order to detection and identification of TSWV on reservoir plants, 37 weed samples were collected from South Khorasan, including Birjand, Sarayan, Ferdows and Ghaen during May and April 2017 and tested by DAS-ELISA. The positive samples in ELISA were tested by RT-PCR and specific primers of Nucleoprotein (N) gene, were amplified a fragments with 777 bp length and sequenced by Macrogene company. Results showed Cadaria draba and Hordeum murinum are infected by TSWV. In Phylogenetic analysis with two isolates and 20 isolates of gene bank two groups were formed. Two isolates of this study, felt in Group II and subgroup A. The closest GenBank isolate was from Montenegro (GU339506) with 97/3 % on Chenopodium Quinoa and the furthest isolate was from Italy (GU36971) on Nicotiana tabacum. This research is the first survey of weeds as a wild host of TSWV in Saffron fields of South Khorasan.