Intra-specific morphological and molecular diversity in brown olive (Olea cuspidata) of Iran

摘要

Brown olive thrives in diverse environmental conditions in Iran suggesting the possible occurrence of genetic diversity in these populations. Moreover in some regions, they occur close to cultivated olive suggesting the possibility of natural hybridization among them. The goal of the present study was to investigate these possibilities. Morphological and RAPD analyses were performed on 8 brown olive populations of Iran using 24 morphological characters. ANOVA test showed significant difference in leaf length and leaf width among different populations and PCA analysis showed that the leaf characteristics (venation, width, trichome, colour in the ventral and dorsal surfaces), number, and distribution of grooves in the endocarp and fruit characteristics (apex, base, and shape) are the most variable characters among the brown olive populations studied. The 38 RAPD primers used produced 541 reproducible bands (loci) out of which 515 bands were polymorphic and 26 bands were common in the populations studied. The Anveh population showed the highest level of polymorphic loci (78%) and the Jareh population showed the lowest value (28%). The highest mean genetic diversity and Shannon information indices occurred in the Anveh population (0.21 and 0.34, respectively) and the lowest values of the same occurred in the Jareh population (0.11 and 0.16, respectively), indicating the presence of a high genetic diversity among the populations studied. The Homag population showed the highest number of specific bands (8 bands). Both morphological and molecular analyses suggested the presence of intra-specific variations.