The diagnostic of viruses in tomato (Lycopersicon esculentum Mill.) by electronmicroscopic and molecular methods

For detection of viral disease agents tomato (Lycopersicon esculentum Mill.) samples of leaves and fruits affected by viral diseases were collected and investigated. Samples of tomatoes exhibiting viral symptoms were found in various growing places. Symptoms associated with viruses inhibited growth, it became evident shoots with short internodes, leaf chlorosis, ringspots, mottling, vein clearing and distortion. The presences of different isometric virions were detected in extracts of tomato samples using transmission electron microscopic (EM) method. Three different viruses of two genera have been identified in L. esculentum crop on the basis of host plant symptoms and morphology of virions. A number of the tomato samples that were found preliminary positive for Cucuber mosaic cucumovirus (CMV), Tomato ringspot nepovirus (ToRSV), and Arabis mosaic nepovirus (ArMV) in biological tests were tested by reverse transcription-polymerase chain reaction (RT-PCR) technique using previously described virus-specific primers. The PCR reactions resulted in the specifically amplification of a 400 bp fragment of CMV RNA, 499 bp fragment of ToRSV RNA and 420 bp fragment of ArMV RNA