Submitted to: Experiment Station Bulletins
Publication Type: Experiment Station
Publication Acceptance Date: June 5, 2009
Publication Date: June 5, 2009
Citation: Mcclung, A.M. 2009. Finding high yield genes in weedy red rice to improve new cultivars. Experiment Station Bulletins. Vol. IV - http://beaumont.tamu.edu/elibrary_default.htm. Technical Abstract: Red rice (Oryza rufipogon) is a weedy, wild relative of cultivated rice (Oryza sativa) that is considered a major pest in rice production fields. However, researchers have found that it can be a valuable source of disease and insect resistance genes. Researchers with USDA ARS and Cornell University have conducted a study that is part of a four year grant funded by the National Science Foundation to determine if O. rufipogon can also be a valuable source of yield enhancing genes that could be used by breeders to develop new rice cultivars. Backcrosses were made between O. rufipogon and the cultivar Jefferson so that a series of breeding lines (NILs) were developed that possessed large pieces of the weedy rice chromosomes inserted into a predominantly Jefferson background. Some 60 NILs were evaluated in yield trials conducted over two years at four locations in Texas and Arkansas. Eleven of the NILs were identified to have significantly higher yield than Jefferson by as much as 23% (yield increases between 840 and 1340 lb/ac). Six of these high yielding lines possessed portions of chromosome 2 derived from O. rufipogon. None of the lines possess any of the undesirable traits associated with red rice like red bran, shattering, dormancy, or rough leaves. The next steps include determining specific chromosomal regions where these yield enhancing genes may occur and whether the yield effect may be, in part, due to other smaller genomic insertions of the weedy parent into the Jefferson background. The best performing lines from this experiment have already been shared with several breeders in the Southern US to ascertain if there is potential for use in their cultivar development programs.