<LI>Evaluation of sweetpotato germplasm collected from around the world and the current germplsm pool at Tuskegee University for desirable characteristics for incorporation into the breeding program. <LI>Development and application of biotechnology and genomic tools in the improvement of sweetpotato. <LI>Develop effective and sustainable pest management approaches for sweetpotato that minimize the reliance on high risk chemical methods, and emphasize alternatives to pesticides without negatively affecting farm income or jeopardizing food safety. <LI> Determine the relationship between the physiological functions and yield of sweetpotatoes. <LI> Evaluation of different cultural practices for sustainable sweetpotato plant and storage root production. <LI>Develop value-added and nutritionally enhanced products from sweetpotato storage roots, peels and leaves. <LI>Develop methodologies and strategies for use of sweetpotato biomass as feedstock for ethanol production.
NON-TECHNICAL SUMMARY: The sweetpotato is an under utilized crop in Alabama. This project uses an integrative and a multidisciplinary approach to develop and improve sweetpotato cultivars that, are pest resistant, have high nutrient content, excellent eating quality, have high dry matter and starch content, are adaptable to varied growing conditions in Alabama and can be used to develop value added and nutritionally enhanced sweetpotato products and as feedstock for biofuel. <P>
APPROACH: We will employ both conventional breeding and biotechnological approaches to breed and select sweetpotato germplasm for high dry matter and starch content, nutritional content and eating quality, disease and pest resistance, suitability for post harvest processing and adaptability to growing in varied conditions in Alabama. Current germplasm pool at Tuskegee University and those collected from around the world will be grown both in the green house and in the field and evaluated for the desirable traits. Polycross nurseries will be established to incorporate the desired traits into adaptable and promising lines. Selected lines will be tested at several locations around the state for adaptability to the various growing conditions. We will use biotechnological and genomic approaches to elucidate the genome structure and organization in the sweetpotato. Genes associated with sweetpotato storage root development, regeneration and pest and disease resistance will be identified and cloned using the Invittrogen TOPO-TA cloning kits. The clones will be sequenced and genes that are specifically linked will be cloned into a plant transformation vector using Gateway Cloning Technology. Agrobacterium-mediated transformation procedures will be used to develop transgenic plants. The transgenic plants will be tested through molecular analysis and in greenhouse and field studies for the desirable traits and selected transgenics will be incorporated into the breeding program. Studies will be conducted to determine the relationship between endogenous cytokinin and nitrogen in their impact on storage root initiation, development and enlargement by characterizing the changes in the ZR levels at different stages of root development. Genomics will be used to study genes related to storage root formation and their regulation. We will conduct studies to collect biomass data on selected sweetpotato cultivars particularly those with high dry matter at different developmental stages to validate and refine the sweetptato growth model for applicability under field conditions. We will compare the impact of organic and inorganic fertilizers and evaluate different planting materials on yield of sweetptatoes. Studies will be conducted to establish pest profiles under varying moisture gradients to elucidate pest response to varying levels of drought and evaluate low-risk and biorational pesticides on sweetptatos. We will use laboratory bioassays and field designs to screen germplasm for resistance to sweetpotato weevil. Value added and nutritionally enhanced products from sweetptato storage peels and leaves will be evaluated for consumer acceptability and also for their functional food properties. We will conduct studies and develop methodologies for using sweetpotato as feedstock for biofuel. Both cellulosic and starch conversion methodologies will be employed for ethanol production.