Diversidade e estrutura genética de populações de araçá (Psidium guineense Sw.) no estado de Perrnambuco

Abstract

The Psidium guineense species, popularly known as strawberry guava, belongs to the Myrtaceae family, which is native to South America having a broad geographical distribution. In the Brazilian Northeast, is found on the coast, in the Forest Zone region. The fruit of the strawberry guava flavor is slightly reminiscent of the guava, although it is slightly more acidic and sharper scent. The culture of strawberry guava (P. guinenese) has no economic significance in the context of the national fruit production, not even existing commercial orchards. It is necessary, studies of genetic population level character, since there is little information on ecological and genetic aspects of the species. In order to provide information on the genetic resources of strawberry guava (P. guineense) in the State of Pernambuco, the objectives of this study were to evaluate the genetic diversity of four natural populations of P. guineense distributed in the Forest Zone of Pernambuco and characterize the genetic structure of these four populations from isozyme markers. Eighteen loci were used to estimate allele frequencies relating to 114 individuals in four populations: Itamaracá Arariba, Marieta and Palmares. Populations had generally high level of polymorphism and average of 1.5 alleles per locus. The heterozygosity observed was higher than heterozygosity expected, which ranged between 0.22 and 0.23 and the heterozygosity expected ranged between 0.34 and 0.40. The fixation index ranged from = -0.794 to = -0.549, presenting all negative, indicating the absence of inbreeding and heterozygosity excess. The estimated population in pairs all showed gene flow are generally high, ranging from Nm = 3.23 to Nm = 20.77 showing a high proportion of migrants among populations.