Figure 3.

Effects of natural genotypic variation in maize for number of crown roots (a) and lateral root branching density (b) on plant performance in the field. Phenotypic variation in the field (a,b). Phenotypes with fewer crown roots had better yield under drought stress (c) and low N stress (e), but worse yield under low P stress (g). Phenotypes with fewer, longer lateral roots had better yield under drought stress (d) and low N stress (f) (note that this graph shows yield as a function root depth expressed as D ₉₅, which is inversely related to lateral root branching density; Zhan and Lynch, ²⁰¹⁵), but worse yield under low P stress. In (g), two phenotypic groups are presented: ‘MS’ for ‘many/short’ lateral roots, and ‘FL’ for ‘few/long’ lateral roots). Data from Gao and Lynch (2016) (c), Zhan et al. (2015) (d), Saengwilai et al. (2014b) (e), Zhan and Lynch (2015) (f), Sun et al. (2018) (g), Jia et al., ²⁰¹⁸ (h). WS, water stress; WW, well‐watered; LN, low nitrogen; HN, high nitrogen. In (h), means with different letters are different at P ≤ 0.05.