Editing Zea (plant) (section)

==Origin of maize and interaction with teosintes==

Maize is a grass, related to [[sorghum]] and more distantly to [[rice]] and [[wheat]]. The genus ''Zea'' is closely related to ''[[Tripsacum]]'', gamagrass.<ref name="Gaut Le Thierry dEnnequin Peek Sawkins 2000">{{cite journal |last1=Gaut |first1=Brandon S. |last2=Le Thierry d'Ennequin |first2=Maud |last3=Peek |first3=Andrew S. |last4=Sawkins |first4=Mark C. |title=Maize as a model for the evolution of plant nuclear genomes |journal=Proceedings of the National Academy of Sciences |volume=97 |issue=13 |date=2000-06-20 |issn=0027-8424 |pmid=10860964 |pmc=34377 |doi=10.1073/pnas.97.13.7008 |pages=7008–7015|doi-access=free |bibcode=2000PNAS...97.7008G }}</ref>

{{clade| style=font-size:100%;line-height:100%
|label1=(Part of [[Poaceae]])
|1={{clade
   |label1= [[BOP clade]]
   |1={{clade
      |1={{clade
         |1=various grasses e.g. [[fescue]], [[ryegrass]]
         |2={{clade
            |1=''[[Hordeum]]'' (barley)
            |2=''[[Triticum]]'' (wheat)
            }}
         }}
      |2=''[[Oryza]]'' (rice)
      }}
   |label2= [[PACMAD clade]] 
   |2={{clade
      |1=''[[Pennisetum]]'' (fountaingrasses, [[pearl millet]])
      |2={{clade
         |1=''[[Sorghum]]'' (sorghum)
         |2={{clade
            |1=''[[Tripsacum]]'' (gamagrass)
            |label2=''Zea'' 
            |2={{clade
               |1=''[[Zea mays]]'' (maize)
               |2=other ''Zea'' species ('''teosintes''')
               }}
            }}
         }}
      }}
   }}
}}

Teosintes are critical components of [[crop domestication|maize domestication]], but opinions vary about which [[taxa]] were involved. According to the most widely held evolutionary model, the crop was derived directly from ''Z. m. parviglumis'' by selection of key mutations;<ref name=Matsuoka2002>{{cite journal |last1=Matsuoka |first1=Y. |last2=Vigouroux |first2=Y. |last3=Goodman |first3=M. M. |last4=Sanchez G. |first4=J. |last5=Buckler |first5=E. |last6=Doebley |first6=J. |title=A single domestication for maize shown by multilocus microsatellite genotyping |journal=Proceedings of the National Academy of Sciences |date=30 April 2002 |volume=99 |issue=9 |pages=6080–6084 |doi=10.1073/pnas.052125199 |pmid=11983901 |pmc=122905 |bibcode=2002PNAS...99.6080M |doi-access=free }}</ref> but in some varieties up to 20% of its [[genetic material]] came from ''Z. m. mexicana'' through [[introgression]].<ref>{{cite journal |last1=Hufford |first1=Matthew B. |last2=Lubinsky |first2=Pesach |last3=Pyhäjärvi |first3=Tanja |last4=Devengenzo |first4=Michael T. |last5=Ellstrand |first5=Norman C. |last6=Ross-Ibarra |first6=Jeffrey |title=The Genomic Signature of Crop-Wild Introgression in Maize |journal=[[PLOS Genetics]]|date=9 May 2013 |volume=9 |issue=5 |pages=e1003477 |doi=10.1371/journal.pgen.1003477 |pmid=23671421 |pmc=3649989 |doi-access=free }}</ref>

All but the [[Nicaragua]]n species of teosinte may grow in or very near corn fields, providing opportunities for [[introgression]] between teosinte and maize. First, and later-generation hybrids are often found in the fields, but the rate of gene exchange is quite low. Some populations of ''Z. m. mexicana'' display [[Vavilovian mimicry]] within cultivated maize fields, having evolved a maize-like form as a result of the farmers' selective weeding pressure. In some areas of [[Mexico]], teosintes are regarded by maize farmers as a noxious [[weed]], while in a few areas, farmers regard it as a beneficial [[Companion planting|companion plant]], and encourage its [[introgression]] into their maize.{{Cn|date=February 2025}}

===Early dispersal of maize in the Americas===

According to Matsuoka et al., the available early maize gene pool can be divided into three clusters:
* An Andean group, that includes the hand-grenade-shaped ear types and some other Andean maize (35 plants);
* All other South American and Mexican maize (80 plants);
* U.S. maize (40 plants)

Also, some other intermediate genomes, or admixtures of these clusters occur.

According to these authors, "The maize of the Andes Mountains with its distinctive hand grenade-shaped ears was derived from the maize of lowland South America, which in turn came from maize of the lowlands of Guatemala and southern Mexico."<ref name=Matsuoka2002 />