*2.1. Plant Material*

We analyzed 208 maize accessions obtained from international and national gene banks in Africa (Supplementary Table S1). The maize panel comprised 190 landraces representing gene pools from Burkina Faso (58), Ghana (43), and Togo (89) (Supplementary Figure S1). The landraces from Burkina Faso and Togo were sourced from the gene bank at the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria, whereas those from Ghana were provided by the Plant Genetics Resources Institute (PGRI) at Bunso, Ghana. The majority of these landraces were collected from farmers' fields in the 1970s and 1980s. However, the eco-geographical data of the collection sites of the landraces were not available. The study also included a diverse set (18) of drought- and heat-tolerant open pollinated populations (hereafter referred to as reference populations) developed by the Maize Improvement Program at IITA (MIP-IITA), Ibadan, Nigeria.
