Caracterização de begomovírus na cultura do tomateiro (Solanum Lycopersicon L.) no estado de Alagoas

Abstract

The begomoviruses are geminiviruses transmitted by whiteflies that present single-stranded circular DNA genome. The begomoviruses reported in Brazil are bipartite, with two genomic components (DNA-A and DNA-B). The explosion of occurrence of begomoviruses was probably triggered by the introduction and spread of vector, the B biotype of Bemisia tabaci. This biotype is polyphagous and greater capacity of multiplication than biotype A (before prevalent in the country). Nowadays, the begomoviruses are considered the most important for tomato crop in Brazil. Presenting high diversity, just for tomato plants 17 species of begomoviruses have been reported, despite the complexity of accurate identification (performed by determining the complete sequence of DNA-A component). The present work aimed the molecular characterization and analysis of genetic diversity of begomoviruses infecting tomato producing areas from Arapiraca, Alagoas. Begomoviruses detection in sintomatic tomato plants was performed by PCR using primers to amplify specific regions of DNA A or DNA B viral genomic components. 23 samples were positive for begomovirus. Accurate identification of species was performed by amplification of the complete genome (DNA-A) using the technique of Rolling circle amplification (RCA), cloning and sequencing of the genome. Two different species of begomoviruses were characterized in this survey and Tomato mottle leaf curl virus was the predominant species among the clones obtained. The other species found was the Bean golden mosaic virus, with only one isolate. This work constitutes the first report of infection of solanaceous by BGMV in Brazil. However, the high sequence identity (99%) of the clone does not eliminate the possibility of contamination. The absence of reports involving infection of tomato plants by BGMV reinforces the importance of conducting further tests to confirm these results.