1a. Objectives (from AD-416):
1. Discover and validate diagnostic biomarkers that predict, diagnose, and/or distinguish apple postharvest physiological disorders (Scientific objective). 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 (Scientific and outreach objective). 3. Estimate the economic impact (both benefits and costs) to the apple industry of utilizing biomarker-based diagnostic tools to manage apple postharvest physiological disorders (Scientific and outreach objective). 4. Activly facilitate transfer of new biomarker-based technology for immediate implementation using current platforms and development of new tailored platforms utilizing biomarker-based technology (outreach objective).
1b. Approach (from AD-416):
Conduct an advisory panel, industry, and academic query that will assess current needs, scope, and understanding of diagnosis and non-chemical management of postharvest browing disorders, representing a variety of similar disorders occurring in multiple economically important cultivars, have been selected for this study. Employ experimental strategies that utilize susceptible cultivars along with chemical and cultural controls that both control the selected disorders while accentuating metabolic differences and differences in gene expression between healthy apples and disorder-prone apples. Comprehensive metabolic and gene-expression profiling will be employed to discover disorder-specific diagnostic biochemical and genetic biomarkers. Metabolic and gene-expression evaluations will be screened by the bioinformatics cooperators. Metabolic and gene expression profiles will be statistically modeled and mined by statistics/modeling cooperator to determine disorder-related metabolic changes and select biomarkers that bestpredict whether an apple will develop a certain disorder of differential that disorder from others. Biomarkers associated with individual disorder will be compiled and compared to select those that will be the bases of discrimination of postharvest browing disorders. An economic study will validate cost-effectiveness biomarker-based management strategies and platforms. New tools will be used to classify or re-classify disorders using the new metabolic information. Diagnostic/prediction biomarkers and tools will be presented to fruit producers, retailers, and agricultural service companies in extension, industry, and scientific meeting to determine the best means for pilot testing and implementation of this new storage management and quality assurance technology.
3. Progress Report:
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. Chemical changes within apple peel and cortex can be exploited to indicate whether there will be significant storage losses due to different browning disorders, before those losses oocur as well as distinguish similar looking browning disorders. Major storage trials of 3 major US apple varieties and 4 economically significant storage disorders have been completed. Evaluation of peel and cortex chemistry under conditions that may lead to disorder development has yielded candidate biomarkers that may be used to assess risk for these disorders. The work of chemical and gene expression analysis and mathematical analysis of the large datasets is ongoing. An assessment of the impact biomarker based tools may have on apple production is ongoing. It is expected that the knowledge gained from this project will enhance our understanding of these disorders to improve how apple producers store fruit, develop new apple varieties with less likelihood of developing these disorders, and provide advanced tools to assess disorder risk. Biomarker based tools for assessing plant health is a relatively novel concept that mirrors medical diagnostics technology and has widespread potential promoting food quality and agricultural sustainability.