2007 Annual Report
Lycopene Increased by Grafting in Watermelons: Cucurbits, especially watermelon, have been grafted for many years in Asia to avoid soil-borne diseases. There is increased interest in vegetable grafting in the U.S. as soil fumigants become limited. Rootstocks have an important influence on the growth and yield of the grafted scion, but quality effects are less well characterized. Scientists at the South Central Agricultural Research Laboratory in Lane, OK, in cooperation with seed company breeders, found that watermelon lycopene could be increased 20 to 80% in fruit from grafted plants, depending on rootstock, scion, and production environment. Lycopene, the red pigment found in watermelon and tomatoes, is a natural food colorant and antioxidant. These results are important in order to maximize lycopene yield and further explore use of grafting as an alternative production strategy. (NP306, Component 2)
Lycopene Formation in Watermelon Chromoplasts: Carotenoids are pigments that give fruit color, protect cells from photoxidation, and are formed in chloroplasts, or chromoplasts, that are microscopic parts of the cell. The arrangement of carotenoids in the chromoplast affects the stability and extraction difficulty of pigments. Carotenoids are most soluble in organic solvents, making removal of solvents after extraction tedious and expensive if carotenoids are used for food products. A scientist at the South Central Agricultural Research Laboratory in Lane, OK, found that watermelon lycopene has a J-type chiral arrangement inside the chromoplast membrane. This type of arrangement allowed binding of a detergent that greatly increased water solubility of the chromoplast. This accomplishment is an important step in advancing economic lycopene extraction for food use. (NP306, Component 3)
b. Scientists actively interacted with local, female, small scale organic grower to help with marketing and production issues in fruit and vegetable production.
Perkins Veazie, P.M., Collins, J.K., Clevidence, B.A., Wu, G. 2007. Watermelons and health. Acta Horticulturae. 731:121-127.
Perkins Veazie, P.M., Roberts, W., Collins, J.K. 2006. Lycopene content among organically produced tomatoes. Journal of Vegetable Science. 12(4):93-106. .
Davis, A.R., Webber III, C.L., Perkins Veazie, P.M., Collins, J.K. 2006. Impact of cultivar and production practices on yield and phytonutrient content of organically grown watermelon. Journal of Vegetable Science. 12(4):83-91.
Collins, J.K., Wu, G., Perkins Veazie, P.M., Spears, K., Claypool, P.L., Baker, R.A., Clevidence, B.A. 2007. Watermelon consumption increases plasma arginine concentrations in adults. Nutrition. 23:261-266.
Collins, J.K., Davis, A.R., Adams, A.L., Maness, N., Perkins Veazie, P.M. 2006. Consumer acceptability of low sugar watermelon sweetened with non-calorie sweetener by a Native American community. International Journal of Food Sciences and Nutrition. 57:(5/6):363-368.
Levi, A., Davis, A.R., Hernandez, A., Wechter, W.P., Thimmapuram, J. 2006. Genes Expressed during the Development and Ripening of Watermelon Fruit. Plant Cell Reports 25:1233-1245.
Fish, W.W. 2006. Interaction of sodium dodecyl sulfate with watermelon chromoplasts and examination of the organization of lycopene within the chromoplasts. Journal of Agricultural and Food Chemistry. 54(21):8294-8300.
Fish, W.W. 2007. Novel procedure for the extraction and concentration of carotenoid-containing chromoplasts from selected plant systems. Journal of Agricultural and Food Chemistry. 55:1486-1490.
Davis, A.R., Collins, J., Fish, W.W., Tadmor, Y.K., Webber III, C.L., Perkins Veazie, P.M. 2007. Rapid method for total carotenoid detection in canary yellow-fleshed watermelon. Journal of Food Science. 72(5):S319-S323.