Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: January 15, 2001
Publication Date: N/A
Technical Abstract: A potentially new gene for resistance to Septoria tritici blotch in wheat was identified in the synthetic hexaploid parent of the W7984 x Opata 85 standard wheat mapping population. The synthetic hexaploid parent, W7984, was virtually immune when inoculated with six isolates of the fungal pathogen Mycosphaerella graminicola (anamorph Septoria tritici) from Indiana, North Dakota and the Netherlands. The Opata 85 parent was highly susceptible. The genetic basis of the resistance was determined by testing 119 F10 recombinant inbred lines from the W7984 x Opata 85 cross. Analysis of the progeny revealed a 61:58 ratio of resistant:susceptible plants, indicating a probable single-gene segregation. Data for the 956 RFLP and other markers already mapped in this population were downloaded from GrainGenes (http://wheat.pw.usda.gov/) and tested for cosegregation with the resistance gene. Linkage was detected with markers located on wheat chromosome 7B. This location was confirmed by analysis of data from 279 microsatellite loci previously mapped in the same population by Roder et al. (Genetics 149:2007-2023). Although the RFLP and microsatellite data sets both mapped the resistance gene to chromosome 7B, none of the molecular markers was located closer than 27 cM from the resistance locus. Bulked segregant analysis with AFLP markers currently is being used to find markers closely linked to the gene, and to define more precisely the map location on chromosome 7B.