Global Warming and Evolution of Wild Cereals

The world's most serious environmental problem is global warming. The domesticated adaptive syndromes in cereals are nonshattering spikes and higher yields. A major outcome of domestication was to increase yields, but this was accompanied by a depletion of much of the genetic diversity in underlying biotic and abiotic resistances that characterized the progenitors. The chapter first overviews briefly the wild progenitors of barley and wheat in the Near East Fertile Crescent, and rice in Asia, and then presents experimental evidence from natural populations of wild cereals affected by global warming. Heading date/flowering time (FT) is an important ecological and evolutionary criterion for regional adaptation and yield in all cereals, with a clear genetic basis identified in both wild emmer and wild barley. Better understanding of human and natural selection and the genes involved is important in the development of crop varieties that are better able to cope with climate change.