Genetic diversity among acerola accessions collected in different states of Brazil using ISSR markers

Currently, commercial acerola orchards have been formed using only one or two genotypes, making these crops highly vulnerable to the occurrence of biotic/abiotic stresses. The characterization of available germplasm using molecular primers can identify alleles of interest, useful in the development of new cultivars. Given the above, the aim of this study was to estimate the genetic diversity of a representative sample of acerola germplasm cultivated in Brazil using ISSR primers. Genomic DNA from 96 accessions conserved in Petrolina-PE was extracted and amplified using 15 ISSR primers. The amplifications were annotated for the presence and absence of bands, making it possible to estimate allelic similarity using the Jaccard index and obtaining a dendrogram (UPGMA method). Analysis of molecular variance was used to quantify genetic variability between and within groups. Genes, GenAlex and Cervus software were used. The accessions were grouped into 24 clusters, with ACO01 and MAR12 being the most divergent and Costa Rica and Flor Branca the most similar. The cluster analysis showed that there was greater variation between individuals collected in the same region, a result confirmed by AMOVA and the Shannon-Wiener Index. The ISSR primers were effective in terms of capturing the distribution of the genetic variation present in the studied accessions. Moreover, considering that they are a representative sample of the acerola germplasm in the country, it is understood that this information provides subsidies for decision-making in the management of genetic resources and in the conduction of acerola breeding programs.