Diversity and host interactions of emerging tomato begomoviruses in Brazil

Over the last decade<span style='color:black'>, t</span>he<span style='color:black'>prevalence and severity of tomato infecting begomoviruses have increased to epidemic proportions and</span>consequently,<span style='color:black'>begomoviruses became one of the major limitations for tomato</span>production throughout<st1:place w:st="on"><st1:country-region w:st="on">Brazil</st1:country-region></st1:place>.<span style='color:black'>The sudden emergence of these</span>whitefly-transmitted geminiviruses followed the introduction<span style='color:black'>and rapid dispersal</span>of the B biotype of Bemisia tabaci.<span style='color:black'>As limited sources of resistance were available, this situation required the development</span>of novel strategies for the disease control including the production of resistant cultivars which should be part of an integrated management approach. These management strategies should be based on a more detailed understanding of the pathosystems involved. Therefore, this PhD research focused on a comprehensive identification and characterization of the begomovirus species involved in the epidemics. Also a study of different aspects implicated in the complex virus-host interactions involving virulence determinants encoded by the virus and the RNA silencing response generated by begomovirus infection in plants was carried out