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Tomato Torrado Virus (tomato + torrado_virus)
Selected AbstractsUltrastructural aspects of tomato leaves infected by Tomato torrado virus (ToTV) and co-infected by other virusesPLANT PATHOLOGY, Issue 2 2010A. Alfaro-Fernández Optical and electron microscopy studies were carried out to investigate the cytopathology induced in tomato leaves infected by Tomato torrado virus (ToTV), a new picorna-like virus associated with the ,Torrado' disease. Infected leaves, showing typical Torrado disease symptoms were surveyed in commercial greenhouses in the main tomato production areas of Spain. The effect of the co-infection of ToTV with other viruses which commonly infect tomato crops was also studied. Ultra-thin sections of ToTV-infected tomato leaves did not show a strong cellular alteration. However, crystalline arrays of isometric virus-like particles (VLPs) of 20,30 nm in the inclusion bodies were observed in phloem parenchyma cells of the infected tissues. Tissues co-infected by ToTV and either Tomato chlorosis virus (ToCV) or Pepino mosaic virus (PepMV) presented more severe cellular alterations. The most deleterious consequences for tomato cells were found in triple infections of ToTV, PepMV and Tomato spotted wilt virus (TSWV), where characteristic cell wall overgrowth was distinguishable, together with a large amount of necrotic cells. [source] Epidemics of Tomato torrado virus, Pepino mosaic virus and Tomato chlorosis virus in tomato crops: do mixed infections contribute to torrado disease epidemiology?ANNALS OF APPLIED BIOLOGY, Issue 3 2010P. Gómez Torrado disease was first observed in protected tomato crops in the Murcia province of Spain in spring 2001, causing serious concern to regional tomato producers. The disease-causing agent was initially identified as a picorna-like bipartite plant RNA virus, now known as Tomato torrado virus (ToTV), but several additional torradoviruses inducing similar disease symptoms have been described more recently. We studied the incidence of torradoviruses between 2005 and 2008 in two parts of Murcia (Spain) where tomato crops are grown commercially. We also analysed the potential association among ToTV, Pepino mosaic virus (PepMV) and Tomato chlorosis virus (ToCV) in samples showing torrado symptoms of varying severity. ToTV was the only torradovirus found in the samples (predominantly as single infections), but double and triple infections comprising ToTV, PepMV and/or ToCV were also detected. There was no evidence of a specific association among the viruses as the frequencies of mixed infections did not deviate from those expected to occur by chance. Statistical analysis of the potential association between torrado symptoms and the type of infection (single or multiple) was inconclusive. To determine whether co-infections with ToTV and PepMV have any marked influence on the torrado disease, we analysed torrado symptom severity and virus accumulation in tomato plants experimentally infected with ToTV-CE, PepMV-Sp13 and PepMV-PS5 in single and mixed infections. The severity of the torrado symptoms was not affected by the presence of PepMV. In single infections, the ToTV titre remained very low, reaching its maximum in the early stages of infection and declining rapidly thereafter, whereas the disease symptoms became more severe over the same timescale. In mixed infections, the accumulation of both ToTV and PepMV was altered with respect to single infections, and the magnitude of this alteration appeared to be virus and strain specific. Therefore, ToTV and PepMV mixed infections may modulate the epidemiology of both viruses in a complex way by altering virus fitness. The impact of our studies on efforts to track and prevent the spread of torrado disease is discussed. [source] | ||||||||||