|Scientific Name||Zea mays|
|Lineage||cellular organisms > Viridiplantae > Streptophyta > Streptophytina > Embryophyta > Tracheophyta > Euphyllophyta > Spermatophyta > Magnoliophyta > Mesangiospermae > Liliopsida > Petrosaviidae > commelinids > Poales > Poaceae > PACMAD clade > Panicoideae > Andropogonodae > Andropogoneae > Tripsacinae > Zea|
|External Links||NCBI; EBI; JGI; PLAZA; Specialized Database|
|Representative Assembly||B73_RefGen_v4||GCA_000005005.5||DNA GFF RNA Protein|
Maize, more commonly known in North America and elsewhere as corn, is a large grain plant first domesticated by indigenous peoples in Mexico about 10,000 years ago. Maize is an economically important crop, along with rice and wheat. It is the premier cash crop in the United States. In addition to being used as grain and fodder, it is also used extensively in pharmaceutical production as well as a commodity feedstock for other organic chemical products like rubber, ethanol and plastic. The six major types of corn are dent corn, flint corn, pod corn, popcorn, flour corn, and sweet corn. The leafy stalk of the plant produces separate pollen and ovuliferous inflorescences or ears, which are fruits, yielding kernels (often erroneously called seeds). Maize kernels are often used in cooking as a starch. Apart from its economic importance, it has been a classical plant model for genetic studies for decades.The maize nuclear genome is thought to be amphidiploid - a fusion of two diploid genomes (Helentjaris T, Weber D, Wright S. 1988) - or allopolyploid - (Wilson WA et al. 1999) with knob heterochromatin. The knob heterochromatin has been characterized as a duplication of a 185-bp element (Peacock WJ et al. 1981) and a 350-bp element (Ananiev EV et al. 1998) with the amount of duplication varying up to 3 to 4 orders of magnitude between different races of corn. This leads to a wide range of genome sizes among corn. The minimum size is estimated to be 2400 Mbp with a high proportion of repetitive DNA.Contemporary US corn crops are the consequence of introgressing various traits into a group of corn varieties. Examination of the pedigrees shows that each is a mixture, in differing proportions, of two ancestral maize strains: northern flint and southern dent [(Allard RW. 1999); (Doebley et al. Econ Bot 1988 42:120-131)]. With the application of inexpensive tools to precisely perform genotypic analysis (Matsuoka Y et al. 2002) the initial findings were confirmed and expanded (Liu K et al. 2003). This investigation was expanded to examine the genetic relationships between individual local populations of different corn land races (Vigouroux Y et al. 2005). The conclusion is that there are five maize land races which arose from independent efforts across the Americas following a single domestication of maize (Matsuoka Y et al. 2002).The first draft of the nucleotide sequence of the Zea mays subspecies mays (maize) genome was announced on February 28, 2007 at the 50th Maize Genetics Conference.