Detecção, caracterização molecular e diversidade genética de begomovirus que infectam fava (Phaseolus lunatus L.)

Abstract

Lima bean (Phaseolus lunatus L.) is one of the four major important grain legumes in Brazil. The occurrence of diseases has difficulted its culture and has affected grain quality of this crop. Among the most important diseases are the viruses, especially those generated from Geminivirus. The high severity of the Geminiviruses diseases is especially due to both the absence of pathogen resistance varieties and increase in the population of a new biotype (biotype B), of the insect vector, commonly named whitefly (Bemisia tabaci). This biotype transmitis the virus more efficiently and it presents a host range larger than biotype A. The present estudy objected the detection, molecular characterization and analisys of the genetic diversity of Begomovirus isolates that infects lima bean plats in Alagoas and Pernambuco States. The detection was realized by PCR technique utilizing as a mold DNA extracted from plants presenting symptoms of geminivirus infection which were colleted from seven locations of Alagoas and one of Pernambuco. It was identified Begomovirus infection in seventeen collected samples. The analisys of genetic diversity, based in PCR-RFLP, revealed that exists diversity among the isolates of Begomovirus that were infecting these plants. According to differences in the patterns of bands generated by PCR-RFLP, it was chosen three isolates (fava Maceió, fava Recife and fava União dos Palmares), in an attempt to sequence analysis. The comparison of the obtained sequences with other deposited in GenBank/NCBI allowed the classification of these isolates as Bean golden mosaic virus, the last one being the first report of infection caused this species in lima bean plants in Alagoas and Pernambuco State.