Submitted to: Arkansas Agricultural Experiment Station Research Series
Publication Type: Experiment Station
Publication Acceptance Date: April 30, 2003
Publication Date: August 11, 2003
Citation: Eizenga, G.C., Lee, F.N., Jia, Y. 2003. Identification of blast resistance genes in rice wild relatives (Oryza spp.) and selected indica lines (o. sativa). Arkansas Agricultural Experiment Station Research Series. 504: 27-32. Interpretive Summary: Interpretive summary not required.
Technical Abstract: Blast, Pyricularia grisea Cav., is a major fungal disease of US cultivated rice (Oryza sativa L.). Blast resistance was observed in some wild relatives of rice (Oryza spp.) and selected indica rice (O. sativa) accessions, indicating these are possible sources of unique blast resistance genes (Pi-genes) which could be incorporated into US rice varieties. Pi-ta, Pi-b, Pi-kh and Pi-z are major blast resistance genes identified in US rice varieties. Objectives of this study are to ascertain the presence of known Pi-genes and identify novel Pi-genes in the aforementioned accessions, and determine the relatedness of these accessions using DNA markers. Preliminary results indicate Pi-ta is present in a few O. nivara and O. rufipogon accessions and at least three indica accessions. Of the other resistance genes, Pi-b, Pi-kh, and Pi-z, one or more are present in about fourteen indica accessions not having Pi-ta and one or two Oryza spp. accessions. Based on the observed blast resistance, there are numerous novel Pi-genes to be discovered in most of these accessions. Preliminary analyses using 183 microsatellite markers indicate the Oryza spp. accessions are very diverse but some indica accessions are closely related to each other. Knowing the relatedness of these accessions will enable rice breeders to incorporate novel blast resistance from more diverse backgrounds into the new rice varieties being developed.