Identification and characterization of lettuce big vein disease (LBVD) in lettuce (Lactuca sativa) crops in Adana and Mersin provinces in Turkey

Abstract

This study was carried out for the purpose of determination of Lettuce big vein disease (LBVD), identification of the virus or virus complex (MiLBVV and/or LBVaV) causing disease and characterization of causal agent in the fields where the lettuce cultivation was made extensively in Adana and Mersin provinces during autumn and winter months between 2015 and 2017. A total of 160 samples were collected from lettuce (Lactuca sativa L.) plants suspected to be infected with LBVD simptomatologically in surveys. In the result of the ELISA tests, 52 samples were found to be infected with MiLBVV. RT-PCR studies were performed to identify the causative agents of LBVD by using specific primer pairs for MiLBVV (MiLBV-F; MiLBVV-R) and LBVaV (VP-248; VP-249) showed that LBVD is caused by MiLBVV or mixed infection of MiLBVV+LBVaV. LBVaV infection was not detected alone in lettuce plants with LBVD symptoms. Sequence analyses showed that Adana and Mersin isolates of MiLBVV formed in separate groups on phylogenetic tree. While Yakapınar (2-MiLBVV 1 E10), Yumurtalık (6-MiLBVV 1 G10) and Yüreğir (4-MiLBVV 1 F10) isolates from Adana province clustered with Argentina and Iran isolates, Yenice 1 (11-MiLBVV 2 H10) and Yenice 2 (12-MiLBVV 2 E11) isolates from Mersin province were in the same group with Netherlands and Egypt isolates in another group. In addition, the Yüreğir isolate of LBVaV (4-VP 248 A12) clustered with isolates from Saudi Arabia, United States, United Kingdom, Australia and Netherlands.