1a. Objectives (from AD-416)
1. Discover and validate diagnostic biomarkers that predict, diagnose, and/or distinguish apple postharvest physiological disorders. 2. Compile sets of biomarkers that could be used to predict, diagnose, or distinguish apple postharvest browning disorders and test their efficacy by classifying/reclassifying browning disorders based on new metabolic/genetic information. 3. Transfer of new biomarker-based technology for immediate implementation adapting existing laboratory-based and field-based analytical platforms.
1b. Approach (from AD-416)
Previous results indicate postharvest experiments designed to produce necessary contrasts can be used to develop viable biomarkers for physiological disorder prediction, diagnosis, and differentiation. Until recently, metabolic and gene expression evaluation approaches have focused on one or a few pathways with known associations to a particular disorder. While focused approaches were insightful, these approaches have not allowed development of new tools for superficial scald control or the discovery of physiological bases of other apparently unrelated physiological disorders. Our proposed research relies instead on comprehensive analytical approaches that avoid preconception of disorder-related metabolic/genetic processes. This allows discovery of prospective biomarkers not previously associated with superficial scald and other disorders.
3. Progress Report
This was granted as a matching non-federal cash contribution for 5350-43000-006-14R. This project relates to objective 1 of the associated in-house project which seeks to identify factors that influence postharvest fruit quality and development of market limiting physiological disorders. Postharvest physiological disorders of apple fruit cause significant annual postharvest losses to susceptible cultivars. Understanding of the genetic and metabolic causes of these disorders and similarities remains sparse. Current treatment practices are not available for organic production, are not acceptable in many markets, or do not provide quality assurance along the supply chain. Biomarker-based storage management tools are expected to provide the US apple industry with additional tools to prevent and predict losses throughout the supply chain. In 2010-2011, experiments were completed to begin selecting gene expression and metabolic biomarkers for superficial scald, external CO2 injury, and firm flesh browning. Metabolic profiling (in-house) and gene expression profiling (by collaborators) for superficial scald and external CO2 injury samples were completed. Two presentations introducing project activities and expected outcomes to stakeholders were given at industry events. Progress was reported at a project meeting held to discuss results to date and future activities. See progress for 5350-43000-006-14R, entitled, "A Diagnostic Toolbox for Integrated Management of Apple Postharvest Necrotic Disorders" for a related study.