Genetics and genomics of wheat domestication-driven evolution

The cereal crops wheat, rice, maize, and sorghum show conservation of large syntenic blocks in spite of more than 40-fold variation in genome and 20-fold variation in chromosome size. It has been proposed that independent mutations at orthologous loci in traits such as shattering, tough fruiting cases (glumes, in the case of wheat), and threshing may have led to domestication-driven convergent evolution. A different picture is emerging from comparative mapping and cloning of these genes in different cereal crops. It appears that these spike traits are controlled by multiple genetic pathways, and mutations at different loci have been selected during domestication-driven evolution.