modifies spike architecture and enhances grain yield in wheat.

Spike architecture influences grain yield in wheat. We report the map-based cloning of a gene determining the number of spikelet nodes per spike in common wheat. The cloned gene is named and encodes a CONSTANS-like protein that is orthologous to in plant species. Constitutive overexpression of the dominant allele but without the region encoding B-boxes in a common wheat cultivar increases the number of spikelet nodes per spike and produces more tillers and spikes, thereby enhancing grain yield in transgenic plants under field conditions. Allelic variation in results in amino acid substitutions leading to differential protein phosphorylation by the protein kinase K4. The allele is present in emmer wheat but is rare in a global collection of modern wheat cultivars.