Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 24, 2008
Publication Date: November 24, 2008
Repository URL: http://riley.nal.usda.gov/nal_web/digi/submission.html
Citation: Jackson, E.W., Wise, M., Bonman, J.M.,Obert, D.E., Hu, G. and Peterson. D.M.. 2008. QTLs Affecting -tocotrienol, -tocopherol, and total tocopherol concentrations detected in the Ogle/TAM O-301 oat mapping population. Crop Science 48:2141-2152. Interpretive Summary: Products containing oat are considered to be beneficial to ones health. This benefit is because oat contains high soluble fiber and good levels of antioxidants, which are known to reduce cholesterol and the risk of cardiovascular disease. One of the antioxidants in oat is tocopherol, better known as vitamin E. Plant scientists would like to increase vitamin E levels in oat through breeding, but this work would require costly and time consuming tests of thousands of breeding lines. One way to overcome this limitation would be to use genetic markers linked to the specific genes responsible for increasing vitamin E levels in oat. Until now, nothing was known about the genes controlling vitamin E isomers in oat. Therefore scientists at the Small Grains and Potato Research Unit in Aberdeen, ID teamed up with scientists at the Cereal Crops Research Unit in Madison, WI to identify genetic markers linked to genes controlling vitamin E, which in turn would be useful in genetic marker based selection. Using an oat mapping population (Ogle1040/TAM O-301) we identified several genetic regions responsible for two of the major vitamin E isomers in oat. Now work needs to be done to convert the available genetic markers into a more user friendly marker type. Once this conversion is complete the makers can be used by plant breeders to select oat lines with higher vitamin E content.
Technical Abstract: Consumption of oat (Avena sativa L.) products has been credited with reducing the risk of various diseases. This may be due in part to tocopherol content. Studies have shown variation in -tocotrienol, -tocopherol, and total tocopherol levels among oat cultivars, however, the genetic basis of these traits is unknown. The objectives of this study were to examine the genetic mechanisms affecting tocopherol levels in the Ogle1040/TAM O-301 population and to identify quantitative trait loci (QTLs) useful for improving tocopherol levels in oat. The population was grown in Aberdeen and Tetonia, ID, over 4 yr. Alpha-tocotrienol, -tocopherol, and total tocopherol contents were measured in harvested seed. Mean levels of all three tocopherol measurements were higher from the irrigated Aberdeen location than from the nonirrigated Tetonia location. One major and four minor QTLs were detected, which accounted for a majority of the -tocotrienol variation across all locations, while six minor QTLs accounted for a majority of the -tocopherol variation. Only one QTL affecting total tocopherol was detected apart from QTLs affecting -tocotrienol and -tocopherol. Overall, we have identified markers linked to QTLs affecting -tocotrienol and -tocopherol. Since the highest level of both tocopherols in lines of the population were higher than from previously tested cultivars, these QTLs should be useful to increase specific tocopherol levels.