| In this study, AFLP technology was used to find markers linked to genes controlling Fusarium head blight (FHB) resistance in Triticum aestivum L. FHB is a disease of cereal crops that results in reduced wheat yields, discoloured, shrivelled kernels, mycotoxin accumulation, and reduced seed and grain quality. Since resistance mechanisms in wheat are complex, often being confounded by environmental effects, and there is high genotypic variance for resistance, molecular markers closely linked to FHB resistance would help in the screening of resistant germplasm. Candidate markers for resistance that were found among three varieties of wheat, two being susceptible to FHB ('Karena' and 'AC Cartier') and one being resistant to FHB (FHB 148), were followed into double haploid (DH) F2 from crosses between each of the susceptible varieties and the resistant variety. These DH lines were evaluated for resistance after inoculation with F. graminearum and MAXR linear regression was done to determine whether any of the candidate markers could explain the variation in phenotype. In the 'Karena'/FHB 148 DH lines, 67% of the polymorphisms segregated in a 1:1 Mendelian fashion (p &ge 0.05), while 50% segregated 1:1 in the 'AC Cartier'/FHB 148 DH lines (p &ge 0.05). In the 'Karena'/FHB 148 population, 35% of the variation in the FHB resistance phenotype was explained by two markers (p &le 0.05), while in the 'AC Cartier'/FHB 148 population, two markers explained 29% of the variation in phenotype (p &le 0.05). Cloning and sequencing of these markers would be useful in the development of cultivars resistant to FHB by marker assisted selection. |
