2017 ASHS Annual Conference

Phloridzin (phloretin 2ʹ-O-glucoside) is unique to apple (Malus ×domestica Borkh.) and its wild relatives. Phloridzin has been researched extensively for its nutraceutical properties, including anti-diabetic, anti-cancer, and antioxidant activities, making phloridzin a potential target for nutritional improvement in new apple cultivars. However, phloridzin accumulates at significantly lower concentrations in fruit than in vegetative tissues and seeds. To understand the variation of phloridzin content in apple fruit and leaves, we surveyed 109 accessions from the USDA-ARS Malus germplasm collection in Geneva, NY from 2015 to 2016 using High Performance Liquid Chromatography. Some of the accessions surveyed were cultivars and sports with a peel disorder termed russet, due to the color of the fruit. In russeted apples, the smooth waxy surface of the fruit is partially or entirely replaced by a corky layer. We observed that phloridzin content tended to be higher in the peels of russeted cultivars than non-russeted. This trend was evident in peels of russet sports compared to their standard-peel counterparts. Peel phloridzin content ranged from 23.5 μg/g FW to 978.8 μg/g FW. We found no significant correlation between leaf and fruit flesh phloridzin content and russeting. Our results suggest that both genetic factors and russeting occurrence and intensity (surface of fruit covered) influence peel phloridzin content.