Resumen en inglés

The objective was to evaluate the variability and genetic structure of P. guajava using microsatellite markers in five subpopulations of San Bernardo del Viento in the department of Córdoba. Forty accessions of P. guajava, DNA was extracted with the chemical method CTAB 2X and the DNA concentration was quantified in a NanoDrop; seven microsatellite markers were amplified by PCR. Then analyzed in 8% polyacrylamide gels in a vertical electrophoresis chamber, the population genetic parameters were calculated, the analysis of molecular variance (AMOVA), the Polymorphic Information Content (PIC) and an analysis of the population genetic structure was performed by Bayesian inference. An average of 3.4 alleles per locus was recorded, a high level of homozygotes was found and a genetic variability of Fst= 0.584 was obtained; the population was not found in Hardy Weinberg equilibrium, this was mainly associated to inbreeding (F= 0.973), the AMOVA test reflected greater variations among individuals with 78%; according to Bayesian inference, all individuals evaluated would present similar genetic groups and the genetic distance allows us to determine that the subpopulations present a reduced gene flow. The population of P. guajava may present a genetic risk due to low heterozygosity indexes and monomorphisms, so it is suggested to implement plans for the preservation of materials in germplasm banks