Evaluation of Genetic Diversity in Olive Germplasm (Olea europaea L.) Using Image Processing and Molecular Markers Based on Physical Properties of Fruits and Stones

Olive (Olea europaea L.) is a historic and significant Mediterranean tree that has been widely used for its curative properties and oily nature. Images of 150 randomly selected fruits were captured and processed in three replications to investigate the genetic diversity among 98 olive genotypes. The difference in all traits between genotypes was significant (P˂0.01), indicating a high level of genetic diversity among the olive genotypes. D1 outperformed other genotypes in terms of fruit area, major axis length, convex area, filled area, and equiv. diameter. The major axis length of the fruit exhibited a significant positive correlation with the perimeter, equivalent diameter, major axis length, and area of the stone (P≤0.01). Also, there was a significant, positive correlation between the minor axis lengths of the fruit and stone. The explained percentage of the traits’ associated markers indicated that the fruits’ major axis length had the highest cumulative coefficient (39%) with five bands. The IJS9-A and ScoT21-B genes regulated the most significant number of traits. The former regulated seven characteristics, i.e. fruit area, major axis length, minor axis length, convex area, filled area, equivalent diameter, and perimeter. In comparison, the latter regulated six characteristics, i.e. fruit area, major axis length, convex area, filled area, and the equivalent diameter of the fruit. Cluster analysis was used for categorizing genotypes into two groups. The findings of this study can be applied in hybridization and production programs for developing genotypes with more suitable fruits.