Reproductive resilience but not root architecture underpin yield improvement in maize (Zea mays L.)

Plants capture soil resources to produce the grains required to feed a growing population. Because plants capture water and nutrients through roots, it was proposed that changes in root systems architecture (RSA) underpin the three-fold increase in maize grain yield over the last century[1][1],[2][2],[3][3],[4][4]. Within this framework, improvements in reproductive resilience due to selection are caused by increased water capture[1][1]. Here we show that both root architecture and yield have changed with decades of maize breeding, but not the water capture. Consistent with Darwinian agriculture[5][5] theory, improved reproductive resilience[6][6],[7][7] enabled farmers increase the number of plants per unit land[8][8],[9][9],[10][10], capture soil resources, and produced more dry matter and grain. Throughout the last century, selection operated to adapt roots to crowding, enabling reallocation of C from large root systems to the growing ear and the small roots of plants cultivated in high plant populations in modern agriculture. ### Competing Interest Statement CM, RC, AS, YF, CG, TT, and GC work for Corteva Agriscience. DMcD is CEO of Phenotyping Screening Corporation. [1]: #ref-1 [2]: #ref-2 [3]: #ref-3 [4]: #ref-4 [5]: #ref-5 [6]: #ref-6 [7]: #ref-7 [8]: #ref-8 [9]: #ref-9 [10]: #ref-10