Agronomic performance and stability of 1A vs. 1AL.1RS genotypes derived from winter wheat 'Nekota'

The presence of the short arm of rye (Secale cereale L.) chromosome one (1R S) has been associated with an increase in grain yield in hard red winter w heat (Triticum aestivum L.). This positive effect has been demonstrated whe n the YRS arm is present in. the 1BL.1RS translocation. However, little inf ormation is available regarding the 1AL.1RS translocation. Our objective wa s to determine the effect of the 1AL.1RS translocation on yield and yield c omponents and their stability across environments. Eighteen homogeneous YA lines (non-1RS) and 16 1AL.1RS lines were randomly derived from the heterog eneous cultivar Nekota. These 34 lines, four composites (1A, 1AL.1RS, 1AL.1 RS + 1A, and Nekota), along with six check cultivars were grown in eight Ne braska environments. The 1AL.1RS translocation in the Nekota background inc reased kernel weight (3.3%) and grain volume weight (0.4%); had no effect o n grain yield, kernels per spike, and anthesis date; and decreased plant he ight (1.2%) and number of spikes per square meter (2.9%). The YA lines and 1AL.1RS lines were equally stable for grain yield, kernels per spike, spike s per square meter, and plant height. For kernel weight, the 1A lines were more responsive and tended to have heavier kernels under favorable environm ents, while the 1AL.1RS lines had heavier kernels under lower yielding envi ronments. For grain volume weight, the 1A lines were more responsive than t he 1AL.1RS lines, which had heavier grain volume weight under lower yieldin g environments. Hence, the 1AL.1RS translocation in Nekota was not benefici al for either agronomic performance or stability.