Project Number: 5350-43000-005-00
Project Type: Appropriated

Start Date: Oct 01, 2006
End Date: Jan 31, 2010

Objective:
The focus of the objectives in this proposal is improving quality and reducing postharvest loss of deciduous tree fruit (chiefly apples, pears and cherries). Our investigations will lead to new knowledge concerning biochemical and molecular causes of physiological disorders, that curative technologies can be developed and implemented, and identification of genes and gene regulatory mechanisms governing such fruit quality characteristics as texture, flavor, and phytonutrient content. Objective 1. Determine how pre- and postharvest factors influence the development of physiological storage disorders of apples. 1.a. Determine effect of pre- and postharvest environment on fruit epidermal tissue development and onset of physiological peel disorders. 1.b. Identify physiological, biochemical and molecular changes during fruit maturation and storage associated with development of internal browning. Objective 2. Identify genes regulating firmness loss and carotenoid metabolism in apple.

Approach:
The tree fruit industry's survival in the United States depends on its ability to develop and utilize new technologies to reduce costs while improving quality. The genetic basis for critical elements determining fruit quality and nutritive value of apple, pear, and sweet cherry fruit is poorly understood and can be addressed using new technologies in molecular genetics that can lead to improved cultivars. We propose to identify influence of preharvest factors on biochemical and physiological changes of fruit epidermis that influence onset of lenticel breakdown in storage by refining experiments to examine changes in wax quality with stress and C2H4 regulators. Refine analytical methods for wax analysis. Identify biochemical and physiological changes during fruit matuation and storage that influence onset of internal browning by repeating first year experiments using whole fruit exposed to CO2 enriched atmospheres and identify oxidizing species accumulating in DPA. Determine proper state of highest quality of fruit agter storage by repeating first year experiments on multiple new cultivars of apples and evaluate the response of newcultivars to various pre- and postharvest conditions. Complete experiments on ethyl bromide alternative for quarantine treatments for effects on fruit quality and storage disorders using microwave energy. Replacing 5350-43000-05-00-D 08/06