Breeding for Tolerance to Abiotic Stress

Soybean is the most widely grown protein and oil crop in the world, and it is, therefore, one of the crops most prone to occurrence of biotic and abiotic stresses. In recent years, with climate change, abiotic stresses have become increasingly common. The objective of this chapter is to discuss important aspects related to the soybean breeding for abiotic stresses, such as water deficit, salt, aluminum, and phosphorus efficiency use. Additionally, it addresses strategies for driving breeding programs focused on the development of tolerant cultivars, employing classic breeding with new tools, such as genomic selection. In this approach, it is essential to know the morphological and physiological changes caused by the stresses and also the mechanisms involved in plant tolerance to them. The genetic basis of these mechanisms is also discussed. In addition, the phenological stage most adequate for plant phenotyping is presented, in order to improve discrimination among genotypes, thus maximizing success in the development of new cultivars tolerant to abiotic stresses.