Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 8/24/1998
Publication Date: N/A
Technical Abstract: Wheat scab is a destructive disease in wheat. Our objective was to identify molecular markers linked to scab resistance by using RILs derived from a cross of Ning 7840 (resistant) and Clark (susceptible). F5, F6, F7, and F10 families were evaluated in the greenhouse for resistance to spread of scab within a spike. Scab symptoms were evaluated four times from 3 to 21 days after inoculation. DNA isolated from both parents and F9 plants was digested with MseI and EcoRI restriction enzymes. Using bulked segregant analysis 300 combinations of AFLP primers were screened for polymorphism. About twenty pairs of primers revealed at least one polymorphic band between the two bulks. A total of 133 RILs were analyzed using AFLPs. Based on the severity frequency distribution, resistance to spread of scab within a spike was controlled by a few major genes. Eleven AFLP markers showed significant association with scab resistance and individually explained up to 53% of the total variation (r). These markers with high R2 values mapped in one linkage group. By interval mapping, one major QTL for scab resistance was identified and putatively mapped to chromosome 7B.