Fruit Crispness Retention of ‘Honeycrisp’ Apple and its Progeny

Abstract

Crispness retention is a unique postharvest trait that ‘Honeycrisp’ apple possesses. With adequate temperature and moisture conditions, ‘Honeycrisp’ fruit retain their highly crisp texture during long-term storage. This research project aims to extend understanding of the molecular mechanisms underlying crispness retention through studying a breeding population derived from ‘Honeycrisp’ x MN1764. In Chapter1, current knowledge regarding postharvest textural changes in apple fruit was reviewed. In Chapter 2, sensory evaluation and instrumental methods were applied to quantify fruit crispness of the breeding population. In Chapter 3, transcriptomes of the selected progeny individuals differed in their ability to retain postharvest crispness were compared to identify genes associated with crispness retention. By combining a genetically-related apple population, an improved phenotyping method for measuring fruit crispness, and transcriptomic analyses (RNA-Seq and nCounter®), we were able to identify novel candidate genes for crispness retention of ‘Honeycrisp’ fruit.