Back to the Future of Cereals

Abstract

The article looks at genomic studies of the world's major grain crops and a technology called marker-assisted breeding as of August 2004. 99 percent of today's agricultural production depends on only 24 different domesticated plant species. Of those, rice, wheat and corn account for most of the world's caloric intake. Plant scientists believe that crop yields have not yet reached their theoretical maximum, but finding ways to achieve that potential increase and to push the yield frontier still further is an ongoing international effort. Improvements may come from tapping the genetic wealth of our crops' wild ancestors by breeding useful traits back into the modern varieties. Human modification of cereal plants through selective propagation and crossbreeding begun during prehistoric times has never stopped. Breeders have been unknowingly altering them by selecting mutations in similar sets of genes. Synteny between genomes of all the grasses allows scientists to consider them as a single genetic system, meaning that any discoveries of genes or their function in one cereal crop could help scientists to understand and improve the others. Such functional genomic studies, combined with sequence comparisons of genes across species, allow scientists to begin developing a basic understanding of how many and which of rice's genes--and by extension those of corn, wheat, sorghum and other cereal crops--contribute to plant development, physiology, metabolism and yield. INSETS: MATCHING TRAITS TO GENES;DESIGNING AND BUILDING NEW CROPS.