Characterization of the Major Dormancy gene at qSD12 in Rice

South Dakota State University, Brookings SD

Investigators

Abstract

Seed dormancy is an arrested state of development that promotes the survival of many wild species, contributes to the persistence of weeds in agro-ecosystems, and provides cereal crops with resistance to pre-harvest sprouting. Weed pests and pre-harvest sprouting damage cause great economic losses in the world and US agriculture. To understand how embryo growth is arrested to maintain the dormant state, a small genomic segment containing qSD12, the quantitative trait locus (QTL) contributing a major effect on seed dormancy, has been introduced from weedy into cultivated rice to characterize the QTL underlying gene. Using a combination of genetic, genomic, molecular biological, and bioinformatic approaches, the novel gene will be pinpointed to a partial high-resolution genetic map and a particular physical interval, determined if it is expressed in single or multiple seed component tissues, and examined for molecular lesions (i.e., changes in DNA sequence) resulted in loss of the function during the evolution and domestication. With the gene information, subsequent research will rovide new insight into physiological and biochemical mechanisms regulating dormancy acquisition and releasing and germination, set the stage to clone additional dormancy loci interacting with qSD12, and test the hypothesis that orthologous genes regulate dormancy and germination in other cereal crops or grasses. Synergistic activities resulting from this project are interdisciplinary collaborations among geneticists, molecular biologists, seed scientists, and breeders, and a major dormancy gene candidate for use in breeding varieties resistant to pre-harvest sprouting. The broader impacts include enhanced opportunities for participation of underrepresented groups in research, and practical training for graduate, undergraduate, and high school students, and high school teachers in biology and agricultural programs.