Genetic diversity of native pitaya from brazilian savannas with basis on markers/Diversidade genetica de pitayas nativas do cerrado com base em marcadores RAPD

Brazilian savanna pitayas naturally vegetate on solid rocky sandstone or quartzite, tree trunks and on rocky fields sand soils at Minas Gerais, Goias, Distrito Federal, Tocantins, Rio de Janeiro and Bahia, with strong evidences that Brazil central region is the biggest pitayas dispersion center, because of the wide phenotypic diversity observed in collected accesses. The objective was to realize genetic diversity study of 13 pitaya accesses maintained at Embrapa Cerrados germoplasm collection through RAPD (Random Amplified Polymorphic DNA) molecular markers. Each access genomic DNA were extracted and fourteen decamer initiators were used to obtain RAPD molecular markers, that were converted in a binary data matrix, from where we estimate genetic distances between accesses and realize grouping and graphic dispersion analysis. 162 RAPD markers were obtained, making 11,57 markers medium per primer. From all the markers, 154 (95,06%) were polymorphic. Genetic distances varied within 0,088 and 0,848, the biggest values observed refer to distance between Unai, MG access and Seleco Embrapa Cerrados access. The most different access was "Unai, MG", that showed 0,675 of genetic distance average in relation to others accessions. The high genetic distance verified is due to the fact that the referred accesses do not belong to the same species. Pitaya accesses groups had little relation to their geographic origin. The genetic diversity found at the Brazilian savannas allows including this biome at pitaya species diversity center, showing good perspectives to studies about this fruit potential.