Serological and molecular detection of Leek yellow stripe virus infecting onion (Allium cepa L.) and leek (Allium ampeloprasum L.) in Ankara, Turkey

Abstract

Onion (Allium cepa L.) has a high economic value in Turkey and it is widely used as main ingredient in Turkish menus. During 2018, 25% of 1.930.695 tons onion production in Turkey was produced in Ankara province. Recently, virus-like symptoms had been observed on onion fields but so far there was no study on onion viral diseases in Ankara province. Leek yellow stripe virus (LYSV) mainly infects leek (Allium ampeloprasum L.) but also infects and potentially causes yield reduction on onion. In August 2018, 45 onion samples show typical viral infection symptoms such as leaf stripes, leaf malformation, yellowing, and dwarfing and six leek samples showing severe yellow leaf stripe were collected from fields in Ankara province. 6 onion and 2 leek samples were positive to LYSV infection in DAS-ELISA. Total nucleic acid was then extracted from samples to be used in RT-PCR using a pair of specific primer to amplify a fragment of LYSV CP region. 6 onion and 2 leek samples were also positive in the RT-PCR by forming specific bands of 1020 bp on agarose gel. The remaining samples did not produce any band on agarose gel, thus were evaluated as negative for LYSV infection. Phylogenetic analysis showed that LYSV Ankara isolates were most similar to isolates from Serbia, Argentina and Germany. This study confirmed LYSV infection in onion and leek for the first time in Ankara province, Turkey.