Banca de DEFESA: ALINE MARQUES MELO

BEHAVIOR OF Phaseolus lunatus to Macroptilium yellow spot virus GENOTYPES AND GENETIC DIVERSITY OF BEGOMOVIRUS IN Macroptilium lathyroides

Geminivirus, Fabaceae, weed, fava bean.

Begomoviruses (family Geminiviridae) are an important genus of viruses that infect cultivated plants in the most diverse regions of the planet, causing significant economic losses in crop fields. In addition to being found associated with cultivated hosts, these viruses are also associated with a wide range of wild/weed hosts, and may serve as alternative hosts or as a source of inoculum for epidemics in commercial crops. In this context, the present study aims to evaluate the response of different fava bean genotypes to infections caused by the begomovirus Macroptilium yellow spot virus (MaYS) and the vector Bemisia tabaci (Middle East-Asia Minor) and to determine the genetic variability of begomovirus infecting Macroptilium lathyroides. In order to evaluate the variability and genetic structure of begomovirus populations infecting M. lathyroides, leaf samples showing symptoms indicative of begomovirus infection were collected in different municipalities of the State of Alagoas in 2019 and 2020. Total DNA was extracted from each sample and served as a template for rolling circle amplification (RCA), then cloned into plasmid vectors and completely sequenced. A total of 39 clones were obtained (29 DNA-A and 10 DNA-B). Paired DNA-A sequence comparisons showed that all isolates belong to a single species: Macroptilium yellow vein virus (MaYVV). Phylogenetic analyzes showed the division of MaYVV isolates into four subpopulations, which showed low values of nucleotide variability. Recombination analyzes showed evidence of intraspecific recombination events in MaYVV isolates The results obtained suggest that the low genetic variability observed for the isolates may have been generated by possible genetic bottlenecks and that the strong geographical structure of the population shows that there is little interaction between the subpopulations and that they may continue to differentiate. To evaluate the response of different lima bean genotypes to infections caused by the MaYSV begomovirus and the B. tabaci (Middle East-Asia Minor) vector, assays will be carried out to evaluate the different responses of MaYSV infection to lima bean genotypes, to to identify a possible resistance of genotypes to the virus. In addition to tests of attractiveness of the vector B. tabaci to the different fava bean genotypes, to determine a possible preference of the whitefly in relation to the different genotypes. With this work we will be able to obtain important results that may have effects on the longevity of disease management strategies.