Developmental Genomics and Metabolomics Influencing Temperate Tree Fruit Quality

The long-term goal of this project is to develop various tools to assist in quality management of deciduous tree fruits. Specifically, during the next five years we will focus on the following objectives. Objective 1: Integrate pre- and postharvest environment and commercial horticultural management practices with genomic and metabolomic regulation of apple and pear fruit quality.[C1; PS 1.A] Sub-objective 1A: Determine how fruit position within the tree impacts pear metabolic profile, superficial scald, postharvest quality, and ripening. Sub-objective 1B: Determine if inconsistent post-storage ripening of 1- methylcyclopropene (1-MCP) treated d¿Anjou pears is relatable to differential absorbance (DA) value at harvest. Sub-objective 1C: Determine if pre-storage light exposure impacts apple peel metabolic responses to postharvest chilling. Objective 2: Enable new apple, pear and sweet cherry fruit biomarker-based quality management strategies. [C1; PS 1.A] Sub-objective 2A: Determine if apple aroma volatile production changes when fruit are stored in environments conducive to development of physiological disorders. Sub-objective 2B: Develop biomarker-based risk monitoring protocols using existing validated gene expression and metabolic biomarkers for early detection of apple and pear peel and cortex storage disorders. Sub-objective 2C: Determine if sweet cherry fruit pitting, cracking and browning is relatable to fruit epidermis and wax composition. The two objectives both rely on metabolomic and genomic techniques to investigate field and postharvest factors that impact fruit quality. The link from sub-objective 2B to 1A reflects biomarkers identified in the previous project period to be validated for apple (2B) as well as applied initially for pear (1A, 2B). Objective 1 is focused on enhancing knowledge of how field horticulture impacts postharvest fruit quality with emphasis on fruit physiological disorders and ripening. The sub-objectives (1A, 1B) are designed to generate new information regarding the impact of pear field horticulture on fruit quality and ripening metabolism, particularly disorder-related metabolomics and genomics. Sub-objective 1C also is focused on generating disorder-related metabolomic information for apple fruit sun damage originating prior to harvest. Application of metabolomic and genomic techniques to disorders arising in the postharvest environment is the basis for Objective 2. Can assessment of apple fruit volatiles accumulating during storage in environments known to cause disorders provide a means to avoid disorder development. (2A) Biomarkers identified for apple disorders in the previous project plan will be validated with multiple fruit lots and cultivars (2B). Disorder metabolism of sweet cherries (2C) will be explored using a metabolomic approach.