Evaluation of intra-cultivar variability in Olea europaea L. cv. Leccino using morphological, biochemical and molecular markers

The phenotypic and genotypic variability of olive tree cv. Leccino (Olea europaea L.), an ancient cultivar from North-Central Italy, was investigated using 44 quantitative and qualitative agro-morphological traits, SDS-PAGE of seed proteins (storage proteins and tegument proteins) and molecular markers such as RAPDs (30 primers) and SSRs (8 primers). Fifteen accessions of Olea europaea catalogued as "Leccino" and one certified tree of "Leccino" (LESt) were examined. The plants were clonally propagated and the measuring of all morphological characteristics was conducted over a period of seven years. The ANOVA analysis showed that all accessions were homogenous for many traits while very few variations were recorded for length of one year old shoots, leaf width, leaf length/leaf width ratio, fruit length, fruit fresh weight, fruit length/fruit width ratio, pit length and pit fresh weight. The PCA analysis and similarity coefficients confirmed a low level of variability of Leccino cultivar. SDS-PAGE analysis of seed proteins showed monomorphic patterns of storage proteins. Protein subunits of teguments revealed a generally high level of similarity as evidenced by Nei-Li coefficient. SSRs and RAPDs markers showed molecular monomorphism among Leccino accessions. The results of agro-morphological, biochemical and molecular nature, taken as a whole, seem to indicate a weakly differentiated/homogeneity of the accessions tested belonging to the Leccino cultivar. The limited morphological and genetic variation could support the assumptions of a monophyletic origin of Leccino cultivar with a genetically restricted base.