Estrutura populacional e obtenção de primers específicos para a identificação de Burkholderia cenocepacia

Abstract

Brazilian production of onion (Allium cepa) in 2017 was 1.72 million tons. In the northeast of Brazil, the agropolo of the San Francisco Valley was responsible for the production of 99.16% of the Northeast region in this same harvest. Losses caused by scale rot can reach 50%. However, some losses may occur during the cultivation and postharvest phase of this vegetable. This work aimed to study the structure of a population of B. cenocepacia isolates from the São Francisco Valley and to design specific primers to identify B. cenocepacia strains IIIA and IIIB.For this, genomic profiles of 63 isolates were analyzed based on REP and BOX-PCR data in the subpopulations of Petrolândia, Belém de São Francisco, Orocó e Casa Nova. Population variability and genetic structure study revealed significant variation between and inside of the subpopulations. The mantel test showed that 26% of population variability is explained by spatial distance. The genetic diversity index reflected the moderate variability of B. cenocepacia populations. The occurrence of gene flow between subpopulations was verified by the number of migrants (Nm) and shared haplotypes, demonstrated gene flow between all subpopulations. For the identification of B. cenocepacia from lineage IIIB and IIIA, were designed primers based on sequences obtained from pangenomic analysis of the complete genome of 17 isolates available from NCBI. Five pairs of primers were obtained, and two pairs were efficient in identifying and separating the lineage. With the understanding of the population structure of B. cenocepacia in the São Francisco Valley and the dynamics through which it evolves and the correct identification of the pathogen, control measures will be adopted more accurately.