|Dubcovsky, Jorge - UNIV. OF CALIF, DAVIS|
|Gieco, Jorge - UNIV. OF CALIF, DAVIS|
Submitted to: Plant Animal and Microbe Genomes Conference
Publication Type: Abstract Only
Publication Acceptance Date: January 14, 2002
Publication Date: N/A
Technical Abstract: Septoria tritici leaf blotch, caused by the ascomycete fungus Mycosphaerella graminicola (anamporph Septoria tritici), is one of the most important diseases of wheat worldwide. Deployment of resistant varieties is the major approach to controlling the disease, yet only one resistance gene has been mapped in wheat so far. A set of 70 F10 recombinant-inbred lines (RILs) derived from a cross between the highly resistant cv. Tadinia (which has the Stb4 resistance gene) and the susceptible parent (UC554 x Yecora Rojo) was evaluated for disease reaction and molecular mapping. The segregation of resistant:susceptible lines following inoculation with an Indiana isolate of M. graminicola conformed to the 1:1 ratio expected for a single major gene. A 1:1 segregation also was observed in a field test in California. Bulked segregant analysis identified a number of amplified fragment length polymorphism (AFLP) markers that were polymorphic between the resistant and susceptible parents and bulks. One AFLP marker amplified with primer pair Eco RI-ACT/Mse I-CAA was 10.6 cM from the resistance gene, and two additional markers flanked the gene at a distance of approximately 31 cM on each side. Searches for other potentially linked AFLP and microsatellite markers and conversion of the most closely linked AFLP into a sequence characterized amplified region marker are in progress.