Abstract
Date palm (Phoenix dactylifera L.) is an important fruit tree in Iraq. Assessment of genetic relationships among date palm cultivars is of major importance for characterization of date palm germplasm, breeding programs, and conservation purposes. Genetic polymorphism in 17 well known date palm cultivars in Iraqi representing ten female and seven male cultivars was assessed using 30 RAPD universal primers and 12 ISSR primers. Results revealed that 86 polymorphic bands were detected by RAPD analysis while 85 bands were observed when ISSRs were used. Correlation fit with a 0.87 r matrix correlation value was observed between RAPD and ISSR data. Therefore, a combined data analysis of both markers was done to assess phylogenetic relationships among cultivars. A total of 2530 scorable bands were generated from both RAPD and ISSR primers with an average of 72.29 fragments per primer. RAPD and ISSR primers were annealed with 240 loci across all cultivar genomes with an average of 6.86 loci per primer. Among these loci scored, 171 loci (71.25%) were polymorphic for at least one of the cultivars with an average of 4.89 polymorphic bands per primer. Genetic distances were estimated using Jaccard’s genetic similarity index and were ranged from 0.422 between the two males 'Risasy' and 'Ghanami Akhhder' to 0.789 between 'Hilawi' and 'Ghanami Ahmer' according to ISSR markers. Unweighted pair group method with arithmetic mean UPGMA ordered date palm cultivars into two main clusters independently of their origin and sex. Moreover, all primer combinations contributed to the discrimination of date palm cultivars, suggesting the efficiency of RAPD and ISSR methods in assessing genetic diversity in Iraqi date palm germplasm.