Background and objective: Pomegranate is grown for its rich flavour in numerous tropical and subtropical areas, like Egypt and the Kingdom of Saudi Arabia (KSA). Assessing the genetic background of the pomegranate is the key to its expansion through the Middle East, where tissue culture reproduction strategies could be used to solve environmental and economic problems. This study aimed at studying the genetic stability of 2 pomegranate genotypes in vitro micro-propagated in the Kingdom of Saudi Arabia by using the random amplified polymorphic DNA (RAPD) polymerase chain reaction (PCR) and inter simple sequence repeats (ISSR) tools.
Materials and methods: The two above mentioned molecular tools were used to evaluate the DNA fingerprints of Taify and Yemeni pomegranate genotypes 12 weeks post in vitro propagation in Taif, Kingdom of Saudi Arabia compared to the mother plant. Shoot tip explants of 4-5 cm long were grown on Murashige and Skoog (MS) medium supplemented by 1.0 mg L-1 NAA, 2.00 mg L-1 IBA and 2 g L-1 activated carbon for 4 weeks for rooting. On 12 weeks DNA extracts were prepared from the acquired plantlets obtained and used as templates for each of RAPD-PCR and ISSR tools.
Results: The RAPD-PCR and ISSR assays generated a total of 79-94 and 57-72 DNA fragments, respectively. In case of RAPD-PCR 80 and 90% of the primers used and developed monomorphic fragments of the Yemeni and Taify genotypes, respectively, particularly OPG08 primer for Taify genotype and OPA04 and OPD07 primers for the Yemeni genotype. Regarding ISSR, no DNA polymorphic for the micropropagated clones were recorded compared to the mother plant.
Conclusion: The ISSR assay's findings indicated the genetic homogeneity between the in vitro micropropagated clones of both pomegranate genotypes and the mother plants.
Keywords: Pomegranate; fingerprinting; genetic homogeneity; micropropagation; molecular tools; polymerase chain reaction; random amplified polymorphic DNA.