Nematode-transmissible virus disease agents detected in some vegetable crops

Abstract

Nematode-transmitted viruses cause economically important diseases in a range of crops worldwide. This study presents the results of detection of nematode-transmitted viruses isolated from some vegetable crops in Lithuania. Samples of cucumber (Cucumis sativus L.), zucchini (Cucurbita pepo L.) and tomato (Lycopersicon esculentum Mill.) crops exhibiting symptoms characteristic of viral diseases were found in various field-grown and greenhouses. Viral diseases were expressed by symptoms of mottling, yellow ringspots, vein necrosis and distortion of leaves. Growth and fruiting of plants were slightly reduced. For identification of virus disease agents traditional (transmission electron microscopy and test-plants) methods and molecular diagnostic (reverse transcription-polymerase chain reaction, RT-PCR) technique were used. Identification of causal agents was based on specific symptoms of infected vegetables, determined experimental host ranges, morphological properties of virions and on cDNA amplified product sizes of nepoviruses in PCRs using virus-specific oligonucleotides. A 499 and 420 bp specific DNA fragments were amplified using isolates from cucumber and tomato samples infected with Tomato ringspot nepovirus and Arabis mosaic nepovirus, respectively.