USE OF DIVERSE GERMPLASM FOR GENETIC IMPROVEMENT OF RICE
Location: Dale Bumpers National Rice Research Center
Title: DNA MARKER IDENTTIFICATION OF ORYZA SPP. FOR INTROGRESSION OF R-GENES
Submitted to: Annual International Plant & Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: October 31, 2003
Publication Date: December 1, 2003
Citation: Eizenga, G.C., Xiang, G., Jia, Y., Lee, F.N. 2004. DNA marker identification of Oryza spp. for introgression of r-genes [abstract]. Annual International Plant & Animal Genome XII Conference. Available: http://www.intl-pag.org/12/abstracts/P5b_PAG12_P393_XI.html.
Rice wild relatives (Oryza spp.) are an important source of novel genes for rice improvement. Previous studies identified resistance to rice sheath blight (Rhizoctonia solani) and rice blast (Magnaporthe grisea) in wild Oryza spp. accessions. Earlier research at the DB NRRC, Stuttgart, Arkansas used a set of 180 SSR markers to genotype 550 rice (O. sativa) accessions with about one half representing germplasm used in US rice breeding programs and one half representing international rice germplasm. These SSRs were used to genotype 56 Oryza spp. accessions found in the US germplasm collection including O. barthii, O. glumaepatula, O. meridionalis, O. nivara and O. rufipogon. Using recently reported markers for blast resistance genes, Pi-ta and Pi-b, data suggest these genes may be present in a very limited number of the Oryza spp. accessions tested. Subsequently, approximately 30 SSR markers were selected from the aforementioned 180 markers to follow the introgression of selected O. barthii, O. nivara and O. rufipogon accessions into cultivated rice (O. sativa) through backcrossing. The O. sativa parent was either Ahrent, a US long grain cultivar or Bengal, a US medium grain cultivar. The 30 SSR markers covered all 24 chromosome arms and were chosen based on polymorphism between the two parents and/or proximity to known R-genes.