Genetic Diversity of Cambuci (Campomanesia Phaea) Revealed by Microsatellite Markers

Abstract

Campomanesia phaea (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 diversity of the species. The 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 out of 14 loci revealed to be polymorphic, disclosing 26 alleles. Based on the allele frequencies, the calculated genetic parameters of the five groups indicated an average allele number per loci (A) of 3.83, with the expected heterozygosity (He) of 0.57 and the observed heterozygosity (Ho) of 0.54. The analysis of the genetic structure indicated that most of the genetic diversity is found within each population (HS = 0.57), whereas the genetic diversity among populations was low (GST = 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, we chose 18 accessions from the five regional populations to compose a core collection that includes most of the genetic diversity found in this study. Our findings may contribute to define better conservation strategies and genetic breeding approaches for this native species in Brazil.