Xie et al. identify the genetic basis of tiller production and survival through a detailed quantitative trait locus (QTL) analysis in a bread wheat × spelt mapping population. In addition to genetic control, a low red:far red ratio (R:FR) is associated with early tillering cessation, few total shoots, high infertile shoot number and shoot abortion. They also determine the trade-offs between fertile shoot number and other yield components. These findings provide a deeper insight into the genetic and environmental determination of tillering dynamics and, in turn, yield potential in wheat.
Tiller production and survival determine final spike number, and play key roles in grain yield formation in wheat (Triticum aestivum).