Assessment of inter- and intra-variations in some olive (Olea europaea) cultivars using molecular markers (ISSR and SCoT)

Genetic variations among and within 15 cultivated olive (Olea europaea L.) genotypes 
distributed in three farms in El-Arish, Egypt were screened using two PCR-based molecular 
markers; Inter Simple Sequence Repeat (ISSR) and Start codon targeted (SCoT). Nine ISSR primers 
and 15 SCoT primers successfully produced 170 (89%) and 347 (91.1%) polymorphic bands.  
Fourty five and 108 positive unique cultivar-specific bands were generated by ISSR and SCoT 
markers, respectively. ISSR 1 and ISSR 18 could characterize genotypes within Chemlali 
population. While, within Manzanillo population, genotypes were differentiated using ISSR 20. On 
the other hand, SCoT2, SCoT4 and SCoT13 could successfully differentiate genotypes within Picual 
population. Moreover, Coratina population was identified by SCoT14 and SCoT22 primers.  PIC 
values, Nei’s gene diversity and Shannon index were   0.21, 1.27 and 0.31, respectively for ISSR 
marker compared to 0.20, 0.17 and 0.29 respectively for SCoT marker. Picual genotypes had the 
highest values of Na (1.29), Ne (1.17), H (0.10) and I (0.16) and Koroneiki population showed the 
lowest values for these parameters (1.20, 1.11, 0.07 and 0.11), respectively. Analysis of molecular 
variance (AMOVA) showed significant genetic variations among (48%) and within (52%) olive 
populations. Dendrogram obtained by UPGMA clustering confirmed the genetic relationships 
among as well as between olive cultivars. This study suggests that combining genetic variations 
data resulting from ISSR and SCoT have a higher potentiality in assessing intra- and inter- varietal 
variations in olive genotypes   supporting continued progress in olive breeding strategies in Egypt.