Genetic diversity assessment in Portuguese Olea europea L. cultivars using the combinatorial β-Tubulin-based polymorphism (cTBP) marker system

Abstract

In Olea europaea L. subsp. europaea var. sativa one of the most outstanding issues for commercial production and product certification lies in clarifying genetic relationships among the highly diverse, cultivated olive material. This report validates the applicability of the combinatorial β-tubulin based polymorphism (cTBP) molecular marker system for Olea europaea L. genotypes. The method is based on the analysis of length polymorphisms resulting from combined amplification of introns 1 and 2 of the β-tubulin genes, followed by fragment resolution in polyacrylamide electrophoresis gel. When compared with other molecular tools the technique is advantageous in terms of low costs and time consumption. The cTBP method was applied on a collection of morphologically classified olive trees (Coleção Nacional de Referência de Cultivares de Oliveira) that are established in the ‘Instituto Nacional de Investigação Agrária e Veterinária’ (INIAV, Elvas, Portugal). The results show that the cTBP marker system is useful to trace genetic variability and phylogenetic relationships in olive material thus able to help clarifying misleading classifications based on morphological characterization. Therefore, the method here presented can be recommended as an efficient tool for commercial applications and scientific studies that aim to verify genetic relationships in Olea europaea L.