Crop Type: Open field crop
Breeding system: Predominantly allogamous
Archaeological and genetic evidence indicate that maize initial domestication started about 9,000 years ago in the Basas river Basin (southwest Mexico) (Kistler et al 2018). Domestication produced a radical transformation from its wild progenitor Zea mays spp. parviglumis, resulting in a plant with a diverse architecture and indehiscent seeds (attached to the spike) and thereby making maize dependent on humans for propagation (Hufford et al. 2012).
Maize was introduced in Europe after the discovery of the Americas, and since then, grown for human and animal consumption. In Europe, during the last four centuries, a number of landraces have been developed to overcome environmental constrains of different areas and to meet specific cultivation needs. Many European maize landraces were maintained by farmers as open-pollinated populations and thus each of them represented a collection of highly heterozygous and heterogeneous plants. Even if a considerable range of variation within population is present, an among populations differentiation is also detectable for many distinctive traits as a consequence of natural and human selection (Lucchin et al. 2003). Currently, such material can still be found cultivated in some marginal areas.
In the last century, maize underwent intense breeding activities that led to the development of high-yielding hybrids adapted to modern agricultural practices and nowadays widely diffused in all cultivation areas.
Maize is a predominantly allogamous species due to the fact that male inflorescence flowers before the female inflorescence.
References- FAOSTAT (2019) Food and Agriculture Organization of the United Nations, FAOSTAT database.
- Kistler L, Maezumi SY, Gregorio de Souza J, et al (2018) Multiproxy evidence highlights a complex evolutionary legacy of maize in South America. Science 362:1309–1313. doi: 10.1126/science.aav0207
- Hufford MB, Xu X, van Heerwaarden J, et al (2012) Comparative population genomics of maize domestication and improvement. Nat Genet 44:808–811. doi: 10.1038/ng.2309
- Lucchin M, Barcaccia G, Parrini P (2003) Characterization of a flint maize (Zea mays L. convar. mays) Italian landrace: I. Morpho-phenological and agronomic traits. Genet Resour Crop Evol 50:315–327. doi: 10.1023/A:1023578207258