Turkish Journal of Agriculture and Forestry

Abstract: In this study, variability in pathogenicity among Fusarium graminearum isolates from different locations in Ohio was determined. The most virulent isolates from these locations were chosen and used in segregation studies to evaluate the resistance of some resistant by resistant winter wheat crosses to Fusarium head scab. Differences in pathogenicity levels were significant among isolates even from the same location. Several generalizations can be made about the segregating generations in this study. The results indicated that Ning 7840 carries multiple genes for resistance. In addition, we found that Freedom and Ning 7840 have at least one resistance gene different. Although the level of resistance observed in the resistant by resistant cross appear to be adequate to protect the cultivar against head scab damage, higher levels of resistance would be useful in the future. As more resistant cultivars are identified, some popular but Fusarium scab suscebtible cultivars, may be replaced.

Key Words: wheat varieties, Fusarium graminearum, head scab, resistance