GENETIC DIVERSITY OF AVOCADO (Persea americana Mill.) IN FOUR AREAS OF ITS NATURAL SPREAD REGION

Abstract

The avocado (Persea americana Mill.) is one of the four major tropical fruits worldwide. The genetic diversity of this Neotropical species is wide and has been difficult to study, so its taxonomy has been complex. In this regard, the use of highly polymorphic genetic markers as microsatellites, allows genetic diversity studies for the species. This study was performed in order to assess the genetic diversity of avocado trees in Zaragoza, N.L., Aquila, Ver., Chochololá, Yuc, y La Antigua Guatemala, using microsatellite
primers. Leaf samples from the four areas were obtained and genomic DNA was extracted. This DNA was amplified with four microsatellite primers (SHRSPa056, SHRSPa089, SHRSPa109 and SHRSPa111). Results were analyzed using the program POPGENE v 3.4. The presence of specific alleles shows that this species has been subject to different domestication processes. In addition, the mosaic of shared alleles indicates similarity among selection and domestication processes that avocado has passed through by the different cultures that used it and molded its diversity and genetic structure. The different allele frequencies showed the genetic interaction among the four localities in study, probably due to open pollination ant its common origin. The presence of unique haplotypes, genetic similarity and genetic drift data provide information to explain the evolution of the species and mark guidelines for future research.