Molecular characterization of progenies of bacurizeiro ( Platonia insignis ) from Marajó Island, northeastern Amazon

ABSTRACT The bacurizeiro (Platonia insignis Mart.) is a tree native to the Amazon whose fruit is much used in the gastronomy in the North and Northeast regions of Brazil. Due to its great economic potential for these regions, the species is being conserved in germplasm banks to support genetic breeding programs. The aim of this work was the molecular characterization of P. insignis accessions belonging to the germplasm bank of the Embrapa Eastern Amazon research unit using ISSR (Inter Simple Sequence Repeat) markers. Seventy-eight accessions of P. insignis belonging to 16 progenies were sampled in two different localities on Marajó Island, state of Pará, Brazil. Among the 16 progenies, seven were collected in Soure and nine in Salvaterra. The 78 accessions were genotyped with 23 pre-selected primers. We obtained 121 amplified products, of which 54 were polymorphic. The most polymorphic primers were UBC 834, UBC 899 and UBC 900. Primers UBC810 and UBC884 did not amplify polymorphic bands. Forty-nine markers out of 54 were selected for genetic analyses. AMOVA within and among progenies showed low genetic differentiation (ΦPT = 0.064, P<0.001) with higher diversity within progenies (96%), low genetic differentiation among sampling localities (ΦPT = 0.025, P<0.013), and higher diversity within (98%) than among localities. Clustering by UPGMA based on Jaccard similarities among pairs of accessions did not separate genotypes according to progeny or sampling localitiy. We recommend that new germplasm surveys consider a greater sampling effort within sampling localitites.