Physiological breeding introduces a new dimension to crop improvement where traits associated with environmental constraints are explicitly targeted. The potential value of physiological characteristics -based on conceptual models- are tested by making strategic crosses that combine as many complementary traits as feasible. The best sources of traits are identified by high throughput and precision phenotyping of genetic resources including exotics. Crossing and subsequent selection of progeny achieve cumulative gene action for yield while expanding the genepool. This approach also permits alternative hypotheses associated with assembling different constellations of traits and alleles to be tested in a realistic breeding context.

Matthew Reynolds is a Distinguished Scientist at the International Maize and Wheat Improvement Centre where his professional goals are to develop and transfer technologies to increase productivity of wheat cropping systems worldwide with a special focus on developing countries. Impacts include a new generation of advanced lines based on physiological breeding approaches to widen the wheat genepool, increased understanding of yield potential and adaptation of wheat to drought and heat stress, development of high throughput phenotyping methodologies, and capacity building. To further these goals he has been active in developing global collaborations to tap into the expertise of plant scientists worldwide –such as the International Wheat Yield Partnership- and is currently coordinating the formation of the Heat and Drought Wheat Improvement Consortium (HeDWIC). He currently leads the community of practice on crop modelling for the CGIAR Big Data platform. He has published widely in the area of crop physiology and genomics and has mentored graduate students through affiliations with universities worldwide. He has also served as a consultant for a number of public and private institutions.​