Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 31, 2001
Publication Date: N/A
Interpretive Summary: Red rice is one of the worst weed problems in rice production in the southern United States. The problem is compounded because the two plants are members of the same species and can interbreed. Red rice lines, hybrids of commercial rice varieties and red rice, and commercial rice varieties were collected from rice producing states. Their genetic relationships were then determined using a DNA fingerprinting technique known as 'microsatellite markers'. Using only 18 microsatellite markers, we were able to distinguish important genetic differences between red rice types based on whether or not their seeds possessed awns, between commercial rice varieties and red rice lines, and could distinguish hybrids of red rice and commercial rice varieties from both red rice and commercial rice. Thus, these markers appear to be useful for detecting and identifying hybrids of red rice. The ability to use these DNA markers to identify specific red rice lines or red rice-commercial rice hybrids may b a powerful tool that farmers could use to identify and manage red rice in new rice cropping systems.
Technical Abstract: Red rice (Oryza sativa L.) is one of the major weed problems in rice production in the southern United States. Red rice accessions were collected from Arkansas and other rice producing states and evaluated at Stuttgart, AR. Seventy-nine red rice accessions and 10 hybrids or putative hybrids between red rice and cultivated rice (RC hybrids) from this collection were analyzed using microsatellite DNA markers developed for cultivated rice (O. sativa) to determine the molecular diversity represented within these accessions and to identify markers that might be useful in identifying hybrids between red and cultivated rice types. Using 18 microsatellite markers, we were able to genetically differentiate between different red rice accessions (awned vs. awnless types), rice cultivars, and RC hybrids. Thus, these markers are useful for detecting hybrids and may be useful for mapping and isolating genes that control favorable characteristics in red rice.