Evaluation of Metaxenia Effects of Canary Island Palm Pollen on Commercial Date Palm Cultivars: Changes in Antioxidant Capacity and Phenolic and Flavonoid Contents of Fruits

To determine the optimum storage conditions of Canary Island palm pollens and their metaxenia effects on the fruit characteristics of commercial date palm cvs. ‘Medjool’ and ‘Barhee’ and the possibility of using the pollen of this species in date palm pollination, the current study was conducted for 2 consecutive years (2020–2021). The results showed that in vitro pollen germination of Canary Island palm is low and storing dried pollens of Canary Island palm at −18 °C proved the optimal temperature for preserving pollen germinability (19%) after 90 days of storage. Based on our results, date palm pollinizer (‘Red Ghanami’) in comparison to Canary Island palm pollinizers significantly increased the percentage of fruit set of crosspollinated ‘Medjool’ bunches, while in the ‘Barhee’ cultivar, no significant difference was observed between the bunches that were pollinated with Canary Island palm and date palm pollinizers. Antioxidant capacity, total soluble solid, total phenolic and flavonoid contents of fruits of the ‘Barhee’ cultivar pollinated with Canary Island palm pollen were higher than date palm pollinizer (‘Red Ghanami’). Overall, in contrast to ‘Medjool’, the ‘Barhee’ cultivar is recommended to be pollinated by Canary Island palm pollens when pollen deficiency occurs in date palm orchards.