ARS | Publication request: Exploring African Rice Genetic Diversity for Genetic Stock Development

Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: November 8, 2010
Publication Date: December 13, 2010
Citation: Eizenga, G.C., Sanchez, P.L. 2010. Exploring African Rice Genetic Diversity for Genetic Stock Development. Plant and Animal Genome Conference. http://www.intl-pag.org/19/abstracts/P05b_PAGXIX_257.html.

Technical Abstract: West African cultivated rice (Oryza glaberrima) and its progenitor species, O. barthii, are a source of genes for crop improvement especially pest resistance (blast, sheath blight, brown spot, bacterial blight, bacterial leaf streak, green leafhopper) and tolerance to abiotic stress (drought, acid soil, seedling vigor). To expand the impact of advances being made in rice molecular genetics, rice seed stocks need to be developed for translational genomics efforts in the background of Asian rice (O. sativa) adapted to the USA. We propose to develop backcross inbred lines to explore the functional basis of the aforementioned desirable traits. In order to select parents from genetically diverse backgrounds, approx. 120 O. glaberrima and 50 O. barthii accessions were genotyped with 36 SSR markers. These markers provided genome-wide coverage and most were previously used to genotype O. sativa collections. A few O. sativa accessions representing the Indica and Japonica subspecies were included as controls. Cluster analysis to determine genetic diversity was conducted with the software PowerMarker. Only O. glaberrima accessions which did not cluster with O. sativa controls were selected for crossing with the U.S. cultivars LaGrue, a tropical japonica adapted to the southern USA and M-202, a temperate japonica adapted to California. The F1 hybrids produced have a high degree of sterility as expected due to the sterility barrier between African and Asian rice. Usually three backcrosses are required to recover adequate fertility. To support the development of SNP markers, seven O. glaberrima and O. barthii accessions were resequenced at the Arizona Genomics Institute.