Incidência e caracterização molecular de badnavírus em bananeira no nordeste do Brasil

Abstract

Brazil is the fourth largest producer of bananas in the world, with emphasis on the Northeast region, which contributes with about 35% of national production. However, the productivity of the crop in the country is considered low, being attributed mainly to phytosanitary problems. The main form of banana crop propagation is by mass micropropagation, which contributes to the accumulation of pathogens, especially viruses. Banana streak is one of the most important viruses of the crop, caused by a complex of nine different species of banana streak virus (BSV) [genus Badnavirus, family Caulimoviridae], which are also transmitted by mealybugs (Pseudococcidae). Although the disease has been present in Brazil for years, studies on the diversity and variability of badnaviruses occurring in banana trees are scarce. Thus, this work aimed to determine the incidence and characterization of badnaviruses that infect banana trees in northeastern Brazil and to obtain the complete genome through high-throughput sequencing using the Illumina platform. Universal primers for the genus Badnavirus and species-specific primers for detection of Badnavirus deltavirgamusae (BSOLV), Badnavirus alphavirgamusae (BSGFV) and Badnavirus betavirgamusae (BSIMV) were tested. As a result, a high incidence of badnavirus infection was observed in all Northeastern states where samples were analyzed, but BSIMV infection was not detected. Samples likely from episomal infections were partially sequenced in the RT/RNaseH region, which shared greater nucleotide identity with BSMYV. A genome containing 7,263 bp was obtained by HTS, which corresponds to the first complete sequence of Badnavirus alphavirgamusae (BSGFV) in Brazil. Keywords: BSOLV, BSGFV, Caulimoviridae, Musa spp., genetic diversity