Increasing Genetic Gains in Wheat through Physiological Genetics and Breeding

Wheat is the cereal that provides 20% of protein and calories to the world population. Wheat production must increase 70% by 2050 to feed the predicted 9.1 billion population. At CIMMYT, to increase yield potential in wheat and to develop stress adapted genotypes, research and breeding is conducted at the International Wheat Yield Partnership (IWYP) platform in collaboration with several national and international partners. Our research on physiological traits focuses on understanding the genetic basis of grain yield based on the conceptual equations derived from harvest index, biomass, and light interception traits as well as application of these in a real breeding program. GWAS, QTL mapping, and genomic enabled and pedigree based selection approaches are used in the program to achieve genetic gains. Physiological breeding focuses on physiological trait based complementary crosses for source and sink traits, to utilize the diversity present in the CIMMYT germplasm. From these crosses seven international nurseries were produced; three based on research under irrigated conditions to increase yield potential (Wheat yield collaboration Yield Trials (WYCYTs) and four abiotic stresses—drought and heat—Stress adapted traits yield nurseries (SATYNs), which were grown in several major wheat growing countries (altogether 120 environments) in South Asia, North Africa, Western Asia, and Mexico. The physiological trait (PT) lines have shown increased grain yield compared to checks in most environments. In this talk, recent studies using GWAS, GS, and pedigree based selection approaches and physiological breeding strategies will be discussed in the frame work of a real breeding program.