Submitted to: Rice Technical Working Group Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: December 15, 2001
Publication Date: June 1, 2002
Citation: FJELLSTROM, R.G., MCCLUNG, A.M., SHANK, A.R., MARCHETTI, M.A., BORMANS, C., PARK, W.D. PROGRESS ON DEVELOPMENT OF MICROSATELLITE MARKERS ASSOCIATED WITH BLAST RESISTANCE GENES. RICE TECHNICAL WORKING GROUP MEETING PROCEEDINGS. 2002. p. 43.
Rice blast is a disease threat to rice production wherever rice is grown in the world. The introgression of genes for blast resistance into improved varieties has been a cost effective and environmentally safe means of controlling crop losses due to this disease. Because blast resistance genes confer resistance to one or more races of blast, several resistance genes are often needed to provide wide-spectrum resistance. Collaborative research between the TAMU Department of Biochemistry and Biophysics and the USDA/ARS in Beaumont, TX has resulted in the development of PCR-based genetic markers associated with several major blast resistance genes in an effort to make breeding for disease resistance more efficient and effective. Microsatellite markers RM138, RM166, RM208, and RM266 are closely linked with the Pi-b gene conferring resistance to blast races IE- 1K and IC-17 located on chromosome 2. Marker RM208 co-segregates with resistance has a unique allele found only in varieties with Pi-b resistance. Microsatellite markers RM144 and RM224 were found to be closely linked both the Pi-kh or Pi-ks genes located on chromosome 11, conferring resistance to blast races IG-1 and IB-54. Germplasm screening results indicate that most varieties with a Pi-k gene have a unique RM144 marker and varieties with the Pi-kh gene have a specific RM224 marker while varieties with the Pi-ks gene have different RM224 markers. Markers RM101, RM155, and MRG6102 were found to be closely linked to resistance to race IB-49, conferred by Pi-ta2. Germplasm with Pi-ta2 resistance share unique markers at RM101 and MRG6102, which flank the Pi-ta2 gene. These markers can be used to select for the presence of major blast resistance genes and have proven to be more reliable than phenotypic disease reactions.