Durum Wheat Breeding: In the Heat of the Senegal River

Global warming may cause +4 °C temperature increases before the end of this century. Heat tolerant bred-germplasm remains the most promising method to ensure farm productivity under this scenario. A global set of 384 durum wheat accessions were exposed to very high temperatures occurring along the Senegal River at two sites for two years. The goal was to identify germplasm with enhanced tolerance to heat. There was significant variation for all traits. The genetic (G) effect accounted for >15% of the total variation, while the genotype by environment interaction (G × E) reached 25%. A selection index that combines G and a G × E wide adaptation index was used to identify stable high yielding germplasm. Forty-eight accessions had a stable grain yield above the average (2.7 t ha −1 ), with the three top lines above 3.5 t ha −1 . Flowering time, spike fertility and harvest index were the most critical traits for heat tolerance, while 1000-kernel weight and spike density only had environment-specific effects. Testing of six subpopulations for grain yield across heat-prone sites revealed an even distribution among clusters, thus showing the potential of this panel for dissecting heat tolerance via association genetics.