Foxtail millet (2n=18), is an annual grass grown both as cereal crop (grain production) and as forage, mainly grown in temperate, subtropical and tropical areas. With about 6,000 varieties, the millet is one member of the Panicoideae tribe, which includes maize (Zea mays), sorghum (Sorghum bicolor), sugar cane (Saccharum officinarum), pearl millet (Pennisetum glaucum) and foxtail millet (Echinochloa colona). Taken as a healthy food, it can supply a nutritious dietary source ranging from starch, protein to various kinds of vitamins and minerals, such as calcium, iron, and sodium. It feeds nearly one-third of the world population with main daily-calories intake, especially prevalence in dry climates or soil-poor regions that are not suited for the cultivation of many other crops. It is a crop with self-pollinating, short lifecycle, small stature and small genome size, all of these favorable attributes makes it more attractive to be an invaluable functional genomics system model, and as a reference genome to aid the sequencing of other larger grasses genomes.

Until today, no crop family has rivaled grasses with regard to agriculture, or has as many evolutionary related genomes sequenced that have diverged to fall into different tribes. The genetic and genomic data on these economically important grass relatives are an invaluable resource for comparative and functional genomics studies. We were interested in tracing the mechanistic evolution of grass genomes and the diversification of species and examining the link between genomic sequence patterns and phenotypes in crops.