SciELO - Scientific Electronic Library Online

 
vol.28 issue6Evaluation of losses caused by two strains of Soybean mosaic virus in two soybean cultivarsSoil and water management as a new tactic, for controlling Meloidogyne incognita in Phaseolus vulgaris author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Fitopatologia Brasileira

Print version ISSN 0100-4158

Abstract

MOREIRA, Silvia R. et al. Characterization of a new Tomato mosaic virus strain isolated from tomato in the State of São Paulo, Brazil. Fitopatol. bras. [online]. 2003, vol.28, n.6, pp. 602-607. ISSN 0100-4158.  http://dx.doi.org/10.1590/S0100-41582003000600004.

Tomato (Lycoporsicon esculentum) plants 'Santa Clara' from the city of Guaratinguetá in the State of São Paulo, Brazil, show typical virus symptoms in this study. The evaluation was carried out by using indicator plants and differential tomato genotypes with resistance factors of Tm-1, Tm-2 and Tm-22 ; virus stability in sap; purification; and negative staining, PTA-ELISA and ISEM. The isolates infected plants from several species of Amaranthaceae, Chenopodiaceae and Solanaceae. Chenopodium amaranticolor plants reacted with local and systemic symptoms; Nicotiana sylvestris and N. rustica reacted with local lesions and the tomato Tm-2 showed immunity. Rod-shaped particles about 300 nm were observed in negatively stained preparations. The isolate reacted against Tomato mosaic virus (ToMV) and Tobacco mosaic virus (TMV) antisera. Based on host plants, the isolate was identified as tToMV and by the tomato genotype response, but it could be not identified as the 0 or I ToMV strain. In order to confirm the identity of the virus, RT-PCR was performed with specific primers for the tobamovirus coat protein gene and the amplified DNA was cloned and sequenced. The nucleotides and deduced aminoacids showed 85 and 91% similarity when compared to ToMV sequences, 75 and 83% similarity with those of TMV, and 67 and 72%, with Odontoglossun ringspot virus (ORSV). For other tobamovirus species, the similarity values were lower than 65%. The virus was confirmed as a new ToMV strain.

Keywords : Tobamovirus; hospedeiras diferenciais; sorologia; seqüenciamento.

        · abstract in Portuguese     · text in Portuguese     · pdf in Portuguese