Molecular identification of Potato X virus in Lithuanian varieties of Solanum tuberosum L. and Lycopersicon esculentum Mill. crops

Abstract

Plants of potato (Solanum tuberosum L.) cultivars ‘Venta’, ‘Goda’ and ‘Vokė’, exhibiting symptoms of greenish-yellow mosaic, were detected at the Vilnius State Plant Varieties Testing Station and private plots. Samples of diseased tomato (Lycopersicon esculentum Mill.) plants of cultivars ‘Laukiai’ and ‘Aušriai’ were found in Kaunas and Vilnius regions. Naturally infected tomato plants had symptoms suggestive of virus infection. Symptoms of infection were exhibited by the general interveinal-yellowing of leaves, bright mottling, reduced leaf size and slightly stunted plant growth. These potato and tomato samples were analysed using transmission electron microscopy (EM) and the reverse transcriptase-polymerase chain reaction (RT-PCR) technique. The identification of the virus was based on results of symptomatology on host-plants, the morphology of virus particle filaments (about 500 nm in lenght) and a specific size of cDNA amplification fragments (360 bp) of virus RNA in RT-PCR. The obtained results indicated that the virus isolated from Lithuanian varieties of potato and tomato plants had properties characteristic of Potato X potexvirus. Keywords: potato, tomato, identification, RT-PCR, Potato X virus