Inheritance of leaf rust resistance in wheat cultivars grandin and CDC Teal

The hard red spring wheat cultivars Grandin and CDC Teal were genetically examined to determine the number and identity of the leaf rust resistance genes present in both wheats. The two cultivars were crossed with the leaf rust susceptible cultivar Thatcher, and the F₁ plants were backcrossed to Thatcher. Fifty-four and 80 BC₁F₁ plants derived respectively from Grandin and CDC Teal were selfed to produce BC₁F₂ families. The BC₁F₂ families were tested as seedlings with isolates of Puccinia 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 families in the seedling tests indicated that Grandin had resistance genes 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 tests, both Grandin and CDC Teal were shown to have adult-plant resistance genes Lr13 and Lr34. Additional leaf rust resistance genes that condition effective field resistance should be incorporated into hard red spring wheat cultivars to diversify the leaf rust resistance in this wheat class.