Leaf tip necrosis and seedling leaf rust resistance conditioned by Lr34 in wheat grown at low temperatures

Wheat leaf rust, caused by Puccinia triticina Eriks., is a common and destructive disease of wheat worldwide. The durable rust-resistance gene Lr34 typically described as an adult plant resistance gene, which not expressed at the seedling stage normal greenhouse temperatures. However, when plants with are grown low temperatures, i.e. approximately 8°C. Lines cultivars demonstrate range responses from near immunity to intermediate reactions on primary leaf. Thatcher-Lr34 isogenic lines ‘RL6058ʹ (Thatcher*6/PI58548) ‘RL6091ʹ (Tc*6/Chinese Spring) were resistant number P. virulence phenotypes under these cool conditions, but susceptible typical A double haploid population cross between ‘Thatcher’ ‘RL6058ʹ, previously genotyped for Lr34, was 8°C screened rust response stage. segregated that corresponds presence allele Lr34. After extended incubation cold progeny also developed distinct tip necrosis; this phenotype absent in plants, similar their reaction plants. When uninfected 10°C, those had extensive necrosis shrunken, sometimes sterile, spikes.