INHERITANCE OF LEAF RUST RESISTANCE IN WHEAT CULTIVARS GRANDIN AND CDC-TEAL

The hard red spring wheat cultivars Grandin and CDC Teal were genetica lly examined to determine the number and identity of the leaf rust res istance genes present in both wheats. The two cultivars were crossed w ith the leaf rust susceptible cultivar Thatcher, and the F-1 plants we re backcrossed to Thatcher. Fifty-four and 80 BC1F1 plants derived res pectively from Grandin and CDC Teal were selfed to produce BC1F2 famil ies. The BC1F2 families were tested as seedlings with isolates of Pucc inia recondita f. sp. tritici that differed for virulence to specific leaf rust resistance genes. The BC1F2 families were also tested in the adult-plant stage in field rust nursery tests. Segregation of BC1F2 f amilies in the seedling tests indicated that Grandin had resistance ge nes Lr2a, Lr3, and Lr10, and was heterogeneous for Lr16. CDC Teal was shown to have the seedling leaf rust gene Lr1. In field rust nursery t ests, both Grandin and CDC Teal were shown to have adult-plant resista nce genes Lr13 and Lr34. Additional leaf rust resistance genes that co ndition effective field resistance should be incorporated into hard re d spring wheat cultivars to diversify the leaf rust resistance in this wheat class.