|Agrama, Hesham - UNIV. OF AR RREC|
|WILSON,JR., C - UNIV. OF AR RREC|
|Estorninos, Jr, L - UNIV. OF AR RREC|
Submitted to: Agricultural Experiment Station Publication
Publication Type: Experiment Station
Publication Acceptance Date: July 26, 2007
Publication Date: August 8, 2007
Citation: Gealy, D.R., Agrama, H.A., Wilson,Jr., C.E., Estorninos, Jr, L.E. 2007. Structure Analysis of Several Red Rice Populations in Arkansas: DNA Marker Evidence for Gene Flow with Rice. University of Arkansas Agricultural Experiment Station Research Series 550:74-83. Technical Abstract: Red rice is a troublesome weed problem in Arkansas rice fields and numerous biotypes are present. Outcrossing between rice and red rice occurs at low rates, resulting in unusual plant types, and can complicate weed management efforts. STRUCTURE analysis of DNA SSR marker data is useful to infer population structure, to assign individuals to different populations, and to identify hybrids. Thus, this procedure was used to evaluate the genetic backgrounds of numerous red rice types that, based on visual traits, apparently had developed from natural outcrossing with rice. STRUCTURE analysis of suspected red rice crosses obtained from a multi-county, multi-state area yielded little evidence that genetic markers initially associated with rice were retained in red rice populations at high levels over time. Additional studies involving a larger number of markers or markers specifically associated with rice cultivars (e.g. semi-dwarfism or herbicide resistance) may be necessary to confirm these preliminary findings. In contrast to the aforementioned results, STRUCTURE analysis clearly showed that a group of red rice plants obtained from Mississippi Co., AR partially shared a genetic background with both long grain commercial rice and red rice, and probably resulted from a recent cross between the two plant types. These studies demonstrate that STRUCTURE analysis can be used to identify and characterize red rice crosses in some cases, and that it could be useful as a diagnostic tool.