Molecular markers: an important tool to analyze the genetic diversity of local Tunisian olive varieties

Abstract

Over the last several decades, climate change has significantly affected Tunisian olive production. Thus, the valorization of local olive resources is paramount to enhance the competitiveness of olive oil quality through unveiling the virtues of local varieties. In this context, we have analyzed the genetic diversity of the predominant local olive trees cultivated in Tunisia using ten preselected microsatellite markers. The screened loci produced a total of 42 alleles, with an average of 4.2 alleles/SSR locus. The principal allele frequency (PAF) passed from 0.66 at (GAPU 59, GAPU71A) to 0.33 at GAPU103A, and the probability of identity (PI) ranged from 0.09 at GAPU103A to 0.33 at GAPU71A. These values are inversely correlated with the polymorphic information content (PIC) and the allelic diversity (AD) data, which reveal the high genetic diversity of local olive varieties. Three main clusters were identified by UPGMA cluster analysis and PCoA. These results allowed the creation of a molecular fingerprint of local olive varieties, which will facilitate the use of genetic selection to improve the agricultural performance of the species Olea europaea L. in our country.