Climate change is expected to alter rainfall patterns with intermittent drought periods becoming more frequent and that not only affects water uptake but also reduces concentrations of available phosphorus (P) in the soil. Future drier climates will therefore aggravate already existing yield limitations caused by widespread P deficiency in soils of Sub-Saharan Africa (SSA). Breeding for adaptive root traits can offer a solution and concepts for ideal root ideotypes exist with ‘steep, cheap and deep’ roots maximizing water and N capture, while a shallow root system would improve topsoil foraging and P acquisition. The validity of these opposite ideotypes has been confirmed in single-stress scenarios but fail when drought and P deficiency coincide.
My talk will introduce our past and present research on root traits in rice, focusing on the key question which root traits may offer opportunities in rice breeding. I will introduce the genomic approaches (genomic prediction) we follow to explore the variation for root traits present in the rice gene pool, give an example on fine-mapping of a lateral root trait and highlight how modelling can aid in selecting influential root traits or trait combinations. I will finish by introducing our ongoing and planned research projects on the topics of lateral root development, drought recovery and mycorrhizal interactions, with practical applications in mind for our model environment, the rainfed rice systems of Madagascar.
