Kernel Evolution: From Teosinte to Maize

Maize is the most productive and highest value commodity crop in the U.S. and around the world: over 1 billion tons were produced each year in 2013 and 2014 (FAO, 2016). Together, maize, rice, and wheat comprise over 60% of the world’s caloric intake (http://www.fao.org). The importance of maize in terms of production and caloric intake is not a recent development. In fact, Native Americans have relied on maize and its ancestor for more than 9000 years. The “Columbian exchange” allowed maize to spread around the world, to adapt to new environments and become a major crop that feeds large portions of the human population. Maize, and the kernel in particular, has undergone dramatic changes over the past 9000 years. The biology of maize seed size and its starch, protein, oil content, and food characteristics, are described in other chapters of this book. Here I review the evolution of maize from teosinte (the wild ancestor) to landraces ( locally adapted, open-pollinated farmer varieties) to modern maize (inbreds and hybrids), and discuss changes in kernel composition and size during this process. 1.2 Domestication