ARS | Publication request: Understanding of evolutionary genomics of invasive species of rice

Submitted to: Rice Technical Working Group Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: December 3, 2011
Publication Date: N/A

Technical Abstract: Red rice is an aggressive, weedy form of cultivated rice (Oryza sativa) that infests crop fields and is a primary factor limiting rice productivity in the U.S. and worldwide. As the weedy relative of a genomic model species, red rice is a model for understanding the genetic and evolutionary mechanisms by which weediness evolves. Previous work has revealed that red rice in the U.S. has two independent evolutionary origins and is likely descended from Asian domesticated rice. We aim to investigate the genetic basis of evolution of weedy rice by addressing the following two questions: What does QTL mapping reveal about genomic regions underlying traits that distinguish weedy rice strains from their putative cultivated progenitors? Do these regions differ for the two independently evolved U.S. weed strains? Thus far we have analyzed the population genomic structure of U.S. red rice, and this information provides a foundation for directly examining the genetic basis by which weediness evolves. Toward this end, we have advanced two mapping populations of the cross of SH (straw hull red rice, 1135-010) and indica (Dee Geo Woo Gen) consisting of 216 individuals and the cross of BHA (black hull red rice, 1996-09) and indica (Dee Geo Woo Gen) consisting of 328 individuals to F5 plants. F6 seedlings of both populations are being advanced in a greenhouse for phenotyping in the summer of 2012. Overall goals and progress of population development and characterization will be presented.