Understanding the effect of rye chromatin in bread wheat

Most experiments on 1RS translocations in wheat (Triticum aestivum L.) cannot separate the effects of introgressions of rye (Secale cereale L.) chromosome arm from the absence of corresponding wheat chromosome arms. The objective of this research was to determine the contribution of individual wheat and rye group 1 chromosome arms. Five group 1 ditelosomics, six substitutions, and 16 translocations of 1R in wheat were compared with appropriate controls. All ditelosomics were significantly different from controls for 100-kernel weight (100-KW), flour protein content (FP), Mixograph peak time (MT) and tolerance (MTO), and sodium dodecyl sulfate sedimentation (SDSS) volume. Among the long arms, 1DL was the most important for end-use quality and 1AL the least important, ranking even below the 1RL tested. The contribution of all short arms was low. Substitutions of 1R negatively impacted agronomic performance with the long arm being entirely responsible for this effect. Among translocation lines, those with 1RS.1BL had the highest yield and those with 1RS.1DL the lowest. Negative impact of all translocations of 1RS on the end-use quality was far greater than the absence of the corresponding IS arms of wheat. Translocation 1RS.1AL was the least detrimental to quality and 1RS.1DL the most detrimental. Both the source of the rye chromatin and its position in the wheat genome affected agronomic performance and quality. These results suggest that it may be possible to create new translocations of 1RS in wheat with improved performance. Translocation of 1RS to 1AL is preferred from a quality point of view; that to 1BL appears more beneficial for agronomic performance.