Autocorrelação espacial das freqüências alélicas em subpopulações de cagaiteira (Eugenia dysenterica DC., Myrtaceae) no sudeste de Goiás

Abstract

Among the many fruit trees from cerrado region that show large economic potential in traditional agricultural systems, the cagaiteira (Eugenia dysenterica DC.) deserves a special place. In this work, spatial autocorrelation analyses were used to evaluate spatial patterns of genetic variation among ten local populations from southeastern Goias State, Brazil. Six isoenzymatic markers (SKDH, 6-PGD, a-EST, MDH, PGI e PGM) were used to evaluate genetic variability, in a total of eight polymorphic loci. Moran’s I coefficients were estimated for four geographic distance classes, and correlograms thus obtained showed clinal patterns of variation for most alleles. Simulations of neutral evolution among local populations were performed using the Ornstein-Uhlenbeck process, both to establish null patterns to test this hypothesis and to define the limits of similarity among correlograms. These analyses showed that population differentiation in this species probably occurred under a neutral process in which local drift is counteracted by low geographic distance gene flow, as in isolation-by-distance or stepping-stone models.