ASHS 2015 Annual Conference

Strawberries are a model system for fleshy fruit in the Rosaceae family. True strawberry fruit are the achenes or “seeds” that cover the surface of a modified receptacle. Strawberries are regularly consumed for their unique flavor and nutritional value. Fruit nutritional quality has been attributed to phytochemicals including micronutrients, antioxidants and specialized polyphenolic compounds present in the fruit. Organoleptic properties, including flavor, aroma, texture, and appearance, are important characteristics for consumers. Fruit nutritional value and organoleptic quality are based on the metabolites present at the ripe harvest stage. Different germplasm and the physiological changes that occur throughout fruit growth and ripening influence the metabolic profile that is important for quality fruit. Despite the importance of phytochemical content, variation in the germplasm and through development of the berry is not well understood. The aim of this work was to screen fruit for desirable chemotype traits that support quality fruit to enhance health benefits, flavor, and post-harvest longevity. The relative contents of metabolites in four different cultivars of strawberry were characterized by measuring detectable vitamins, amino acids, and polyphenols using ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry profiling in achene and receptacle tissues. Differences in cultivars support the idea that breeding for quality enhancing metabolite content is possible because much variation can be explained by genetic differences. The majority of health-promoting phytochemicals are present in receptacle strawberry tissue. Polyphenols including flavonoids and ellagitannins were abundant in the ‘Strawberry Festival’ receptacle and Winterstar™ cultivar achenes, while vitamins were present primarily in ‘Florida Radiance’, Sensation™, and Winterstar™ receptacle. The presence of procyanidin pentamer in only ‘Strawberry Festival’ highlights the uniqueness of the varietal, despite relatedness to other cultivars. Breeders can use these findings to select germplasm for traits like high vitamin content or anthocyanidin content compared to other popular cultivars. Consumers prefer a sweet, flavorful strawberry that lasts. Selective breeding can deliver the ideal berry incorporating Winterstar™ germplasm, which has high polyphenolic content, to promote increased post harvest shelf life.