Plant & Animal Genome V Conference
Town & Country Hotel, San Diego, CA, January 12-16, 1997.
PAG-V: P32 - ANALYSIS OF DEFENSE RELATED GENES FOR ASSOCIATION WITH LOCI FOR DURABLE RATE REDUCING RESISTANCE TO SUDDEN DEATH SYNDROME.
P32
ANALYSIS OF DEFENSE RELATED GENES FOR ASSOCIATION WITH LOCI FOR DURABLE RATE REDUCING RESISTANCE TO SUDDEN DEATH SYNDROME.
TORTO, GERTRUDE, VICTOR NJITI, David A. Lightfoot
Southern Illinois University at Carbondale, IL62901-4415
Late season rate-reducing resistance to Fusarium solani (Mart.)Sacc. f. sp. phaseoli (Burk.) Snyd. & Hans underlies field resistance to soybean (Glycine max (L.) Merr.) sudden death syndrome. Loci isolated in near isogenic lines show the genes underlying rate reducing resistance are simply inherited and correspond to some but not all QTL underlying SDS resistance. One locus that does not contribute to rate reducing resistance appears to contribute to toxin resistance. Some of the genes mediating rate-reducing resistance are likely to be regulated by transcription. Our objective was to determine whether plant defense related genes or genes induced by F. solani infection could be associated with this resistance mechanism. Therefore, differential display PCR was used to detect mRNA molecules associated F. solani infection of resistant cultivars. Thirteen pairs of primers were used to detect about 750 mRNAs. About 0.3% of mRNA molecules detected were constitutive to resistant genotypes, about 2% accumulated in response to infection of resistant genotypes by F.solani and about 0.6% were reduced by infection. Six of these anonymous mRNA molecules as well as six known plant defense genes were used as RFLP probes in QTL analysis of SDS resistance. Probes that map within 1 cM of two major resistance QTL have been detected and will be analyzed as candidate resistance genes and/or probes to facilitate positional cloning of the underlying genes.