show Abstracthide AbstractFoxtail millet, <i>Setaria italica</i>, is a C4, inbreeding, panicoid crop with a small diploid genome (1C genome = 490 Mb). It is thought to be closely related to bioenergy grasses such as <i>Panicum virgatum</i> (switchgrass), <i>Pennisetum purpureum</i> (napiergrass), and <i>Pennisetum glaucum</i> (pearl millet) yet has a smaller diploid genome. Switchgrass differs from other panicoid grasses exhibiting C4 photosynthesis in the decarboxylation enzyme (NAD-malic versus NADP-malic) thus making foxtail millet important to understand this important trait. Foxtail millet is also one of the oldest domesticated crops with archeological remains from 7,500 to 7,900 years BP in northern China.