Climate and salinity effects on color and health promoting properties in the pomegranate (Punica granatum L.) fruit arils

Pomegranate (Punica granatum L.) has recently become a commercially important crop due to multitude health promoting properties attributed to different parts of the fruit. Worldwide pomegranate production has expanded greatly in traditional and new locations of diverse climatic and water conditions. The pomegranate industry demands intensely red fruit with high antioxidant content. It is therefore especially important to investigate the effects of climate and water quality on pomegranate anthocyanin and phenolics accumulation. Our research has focused on the edible part of the fruit, specifically, the arils. A diverse selection of pomegranate cultivars was employed. To explore climate effect, fruit that developed and ripened under a wide range of temperature regimes were studied. To explore water quality effect, fruit from plants irrigated with a wide range of salinities, 0.5-9 dS m-1, were studied. Anthocyanins were analyzed by RP-HPLC and phenolics content was determined by the Folin-Ciocalteau assay. Both abiotic factors considerably affected arils' composition. Cooler temperatures enhanced both pigment and antioxidant accumulation. Climate also affected anthocyanin composition. Increased salinity enhanced phenolics accumulation in both accessions but reduced that of anthocyanins in a cultivar dependent manner. Our results can benefit breeding and agricultural efforts to enhance pomegranate fruit quality, especially, in face of global warming and water quality deterioration.