EFFECT OF 1BL.1RS ON AGRONOMIC PERFORMANCE OF SOFT RED WINTER-WHEAT

The wheat (Triticum aestivum L.)-rye (Secale cereale L.) translocation , 1BL.1RS, has been reported to enhance yield potential in hard wheat germplasms. This study was designed to evaluate the impact of 1BL.1RS on yield potential in soft red winter wheat. Agronomic traits associat ed with yield potential were measured in 40 F-9-derived sister lines i n two soft red winter wheat genetic backgrounds, SW85294 and SW85*562 6. The presence of 1BL.1RS had no significant impart on grain yield, k ernel weight, biological (total above-ground) yield, harvest index, fe rtile tillers, spikelets per head, or kernels per spikelet. This effec t was independent of production environment in which the translocation was assessed. The presence of the translocation caused a 3.3- and 4.0 -cm reduction in plant height in SW855626 and SW85*294, respectively. A significant reduction in lodging was associated with reduced height . Heading date was delayed approximate to 1 d in SW85294 but was not affected in SW855626. The effect of genetic background was large rela tive to the effect of the translocation for all traits measured. These data suggest that where grain yield is a primary objective of the bre eding program, emphasis should be placed on selection for genes on oth er wheat chromosomes rather than for the presence of the 1BL.1RS trans location.