Genetic diversity of cambuci [ Campomanesia phaea (O. Berg) Landrum] revealed by microsatellite markers

Campomanesia phaea (O. Berg) Landrum (Myrtaceae), known as cambuci, is a native species from the Brazilian Atlantic Forest with great potential to be developed as a new fruit crop. Microsatellite markers were developed for cambuci to characterize the genetic diversity and to investigate the genetic structure of a group of accessions originally collected at the presumed center of the species diversity. This work involved the collection of 145 accessions from five regional groups (Juquitiba, Paraibuna, Mogi das Cruzes, Ribeirão Pires, and Salesópolis) in São Paulo state, Brazil. Fourteen loci were identified in an enriched genomic library developed from one of these accessions. Six of the 14 loci were polymorphic, disclosing 26 alleles. Based on the allele frequencies, the calculated genetic parameters of the five groups indicated an average allele number per locus (A) of 3.83, with an expected heterozygosity (He) of 0.57 and observed heterozygosity (Ho) of 0.54. Analysis of the genetic structure indicated that most of the genetic diversity was found within population (H S = 0.57), whereas the genetic diversity among populations was low (G ST = 0.19). The genetic diversity parameter of Nei was considered low for the cambuci analyzed populations, with no evidence of inbreeding. Based on Darwin analysis, 18 accessions were chosen from the five regional populations to compose a core collection that included most of the genetic diversity found in this study. Our findings may contribute to defining better conservation strategies and genetic breeding approaches for this native species in Brazil.