The date palm (Phoenix dactylifera L.), 2n=36, is a dioecious long-lived monocotyledonous plant. It is a dioecious plant with male and female flowers borne on separate palms. In commercial plantations, artificial pollination is essential for economical yield, since the female inflorescences are hand pollinated with selected pollen from males. It is generally known that pollen from different sources affects the yield and fruit quality. The pollen sources influences the size and shape of the seeds which is known as the xenia effect, and directly affects fruit set, yield and fruit physical and chemical characteristics referred to as the metaxenia effect. Many experiments have shown that no constant trend is detected for the genetic relationship between the pollen sources and commercial female cultivars. There is a clear relationship between them due to the ecogenetics (gene-environment interactions) for both the selected pollen source and the commercial female cultivar. The phylogenetic relationships among date palms can be investigated through fingerprinting analysis using RAPD. The RAPD–PCR can detect the genetic variability and the relationships among date palms, and also estimate the expression of similarity using the Dice coefficient. PCR is an enzymatic reaction, so the outcome can be significantly influenced by the quality and concentration of template DNA, PCR component concentrations and PCR cycling conditions.