Submitted to: American Society of Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/28/2004
Publication Date: 10/31/2004
Citation: Eizenga, G.C., Lee, F.N., Jia, Y., Yan, W. 2004. DNA markers identify blast resistance genes and genotype newly introduced rice germplasm [abstract] Agronomy Abstracts. 2004 CDROM.
Technical Abstract: Blast, Pyricularia grisea Cav., is a major fungal disease of cultivated rice (Oryza sativa L). Resistance to US blast races was observed in 94 newly introduced cultivated rice accessions, indicating these accessions are possible sources of unique blast resistance genes (Pi-genes) that could be incorporated into US rice varieties. Pi-ta and Pi-b are major blast resistance genes that have been characterized molecularly and introduced into US varieties. Objectives of this study were to identify Pi-ta and Pi-b in the aforementioned accessions and determine their relatedness using SSR markers. Pi-ta, pi-ta and/or Pi-b alleles were detected in 60 accessions using dominant/recessive gene markers indicating their resistance was not new. Of the remaining 34 blast resistant accessions, 26 originated in China and potentially contain novel blast resistance genes for utilization by US rice breeding programs. Genetic distance, as determined using 111 microsatellite markers, indicated some accessions had a diverse origin and many of these had good agronomic characteristics. As many as 32 accessions were identified as excellent potential sources for incorporating novel resistance to blast into advanced US rice breeding lines.