Evaluation of Langdon dumm-Aegilops tauschii synthetic hexaploid wheats for reaction to tan spot, Stagonospora leaf blotch, leaf rust, stem rust, and Hessian fly.

摘要

Langdon dumm-Aegilops tauschii synthetic hexaploid wheats (SHW) (AABBDD genomes) developed by L.R. Joppa in the 1980s were evaluated for seedling resistance to multiple diseases and Hessian fly. Langdon was moderately susceptible to tan spot, susceptible to Stagonospora leaf blotch, resistant to stem rust and leaf rust, and susceptible to Hessian fly. The SHWs showed average tan spot and Stagonospora leaf blotch reactions ranging from 1.33 to 4.17 and 1.67 to 4.67 (1-5 scale), respectively. The SHW lines, like Langdon, gave resistant to moderately resistant reactions to all races tested for stem rust. Langdon gave a resistant response to all isolates tested for leaf rust, but some SHW lines showed moderately susceptible reactions to some isolates. Hessian fly inoculations revealed three SHWs to be highly resistant to the Great Plains biotype. These results indicate that some Ae. tauschii accessions are contributing resistance against Stagonospora leaf blotch, tan spot and Hessian Fly. Because resistance was present in the durum parent, it was impossible to identify Ae. tauschii stem rust or leaf rust resistance found in the SHW lines. These lines should prove useful for incorporation into breeding programs for crop improvement.