Evolution of competitiveness during wheat domestication

• Domesticated wheat plants are stronger competitors than their wild relatives • Stronger competitive ability evolved early during the domestication process • Competitiveness increased through larger, steeper leaves and apical dominance • Modern wheat breeding has weakened competitiveness for high-density planting Domesticated wheat plants are stronger competitors than their wild relatives Stronger competitive ability evolved early during the domestication process Competitiveness increased through larger, steeper leaves and apical dominance Modern wheat breeding has weakened competitiveness for high-density planting Crop domestication involved adaptation of wild plants to human exploitation, 1 1. Harlan, J.R. ∙ de Wet, J.M.J. ∙ Price, E.G. Comparative evolution of cereals Evolution. 1973; 27 :311-325 Google Scholar , 2 2. Purugganan, M.D. ∙ Fuller, D.Q. The nature of selection during plant domestication Nature. 2009; 457 :843-848 Google Scholar , 3 3. 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Here, we used real and virtual experiments to test the hypothesis that cultivation selected for stronger competitive ability in wheats. First, we compared three independent domestication events across wheat species, showing that domesticated landraces were stronger competitors than their wild counterparts. Model simulations reproduced this finding, showing that competitiveness increased through larger, more erect leaves and greater apical dominance. A second experiment compared wild, landrace, and elite durum wheats, finding that stronger competitiveness arose early during domestication but has been reversed by modern breeding. Simulations showed that weaker competitiveness in modern varieties arose from smaller leaves and shorter internodes. Our work indicates that competition selected for domestication traits responsible for wheat canopy growth and architecture, resulting in competitive landrace phenotypes unsuitable for conventional modern agriculture.