Towards an Architectural Approach to Direct Maize Breeding for Cold Tolerance

In high latitude environments, maize grain filling occurs when light is decreasing and water availability may be limiting. An improvement in cold tolerance would allow earlier sowing and thus a better fit of the crop growth cycle to the environment. A field experiment with two planting dates was conducted using four maize inbred lines of temperate or highland-tropical origins. Early sowing had a major effect on plant growth and light interception, both during and after the cold period. Less striking effects were observed on phenology, mean leaf angle and radiation use efficiency. 3D virtual plants coupled with a radiative model are proposed as a tool to analyze the quantitative impact of genetic variability in different traits on light interception of early sown crops. The potential contribution of virtual plants to drive genetic studies and plant breeding for cold tolerance is discussed.