Editing Zea (plant)

{{Short description|Genus of flowering plants in the grass family Poaceae}}
{{Redirect|Teosinte}}
{{Automatic taxobox
| image = Corncobs edit1.jpg
| image_caption = ''[[Zea mays]]''
| display_parents = 4
| taxon = Zea (plant)
| authority = [[Carl Linnaeus|L.]]
| type_species = ''[[Zea mays]]''
| type_species_authority = [[Carl Linnaeus|L.]]
| synonyms_ref = <ref name=y>[http://apps.kew.org/wcsp/synonomy.do?name_id=450340 Kew World Checklist of Selected Plant Families]{{dead link |date=January 2025}}</ref>
| synonyms = * ''Euchlaena'' <small>Schrad.</small>
* ''Mays'' <small>Mill.</small>
* ''Mayzea'' <small>Raf.</small>
* ''Reana'' <small>Brign.</small>
* ''Thalysia'' <small>Kuntze</small>
* × ''Euchlaezea'' <small>Jan.Ammal ex Bor</small>
* ''Mais'' <small>Adans.</small>
}}

'''''Zea''''' is a [[genus]] of [[flowering plant]]s in the [[Poaceae|grass family]]. The best-known species is ''Z. mays'' (variously called [[maize]], corn, or Indian corn), one of the most important crops for human societies throughout much of the world. The four wild species are commonly known as '''teosintes''' and are native to [[Mesoamerica]].

==Etymology==
''Zea'' is derived from the [[Greek language|Greek]] name ({{lang|el|ζειά}}) for another cereal grain (possibly [[spelt]]).<ref name="gledhill">Gledhill, David (2008). "The Names of Plants". [[Cambridge University Press]] (CUP). {{ISBN|9780521866453}} (hardback), {{ISBN|9780521685535}} (paperback). pp 411</ref>

==Recognized species==
[[File:Maize-teosinte.jpg|thumb|teosinte (top), maize-teosinte hybrid (middle), [[maize]] (bottom)]]
The five accepted [[species]] names in the [[genus]] are:<ref>{{Cite web|url=https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=42268#null|title = ITIS - Report: Zea}}</ref><ref name="Wu-et-al-2011" /> 
{| class="wikitable"
|-
! Ear !! Plant !!  Scientific name !! Common name !! Distribution
|-
| [[File:Perennial Teosinte ear (Zea diploperennis) - Detail.jpg|120px]] || [[File:Zea diploperennis01.jpg|120px]] || ''[[Zea diploperennis]]'' <small>H.H.Iltis et al.</small>|| diploperennial teosinte || [[Jalisco]]
|-
| [[File:Pl. I Report of the Commissioner of Agriculture (U.S.) 1887.jpg|120px]] || || ''[[Zea luxurians]]'' <small>(Durieu & Asch.) R.M.Bird</small> ||  Maíz de Monte, Florida teosinte and Guatemalan teosinte || [[Chiapas]], [[Guatemala]], [[Honduras]]
|-
| [[File:Maize J7.jpg|120px]] || [[File:Belize - panoramio (47).jpg|120px]] || ''[[Zea mays]]'' <small>[[Carl Linnaeus|L.]]</small> || Corn, Maize || southern [[Mexico]], Guatemala; cultivated in many places
|-
| || || ''[[Zea nicaraguensis]]'' <small>H.H.Iltis & B.F.Benz</small>|| Nicaraguan teosinte || [[Nicaragua]]
|-
| || [[File:Zea perennis.jpg|120px]] || ''[[Zea perennis]]'' <small>(Hitchc.) Reeves & [[Paul Christoph Mangelsdorf|Mangelsd.]]</small>|| perennial teosinte || Jalisco
|-
|}

[[Maize]] (''Zea mays'') is further divided into four subspecies: ''[[Zea mays subsp. huehuetenangensis|Z. m. huehuetenangensis]]'', ''[[Zea mays subsp. mexicana|Z. m. mexicana]]'', ''[[Zea mays subsp. parviglumis|Z. m. parviglumis]]'' (Balsas teosinte, the ancestor of maize), and ''[[Zea mays subsp. mays|Z. m. mays]]''.<ref name="Wu-et-al-2011"/> The first three subspecies are teosintes; the last is [[maize]], or corn,<ref name="Wu-et-al-2011">{{cite journal |last1=Wu |first1=Chi-Chih |last2=Diggle |first2=Pamela K. |last3=Friedman |first3=William E. |title=Female gametophyte development and double fertilization in Balsas teosinte, ''Zea mays'' subsp. ''parviglumis'' (Poaceae) |journal=[[Sexual Plant Reproduction]]|date=September 2011 |volume=24 |issue=3 |pages=219–229 |doi=10.1007/s00497-011-0164-1 |pmid=21380710 |s2cid=8045294 }}</ref> the only domesticated [[taxon]] in the genus ''Zea''.{{Citation needed|date=January 2021}}

The genus is divided into two [[section (botany)|sections]]: ''Luxuriantes'', with ''Z. diploperennis'', ''Z. luxurians'', ''Z. nicaraguensis'', ''Z. perennis''; and ''Zea'' with ''Z. mays''. The former section is typified by dark-staining knobs made up of [[heterochromatin]] that are terminal on most [[chromosome]] arms, while most subspecies of section ''Zea'' may have none to three knobs between each chromosome end and the [[centromere]] and very few terminal knobs (except ''Z. m. huehuetenangensis'', which has many large terminal knobs).{{Citation needed|date=January 2021}}

==Description==
[[File:ZeaSeedls400x99.jpg|thumb|Microscopic view of ''Zea'' seed]]

Both [[Annual plant|annual]] and [[perennial plant|perennial]] teosinte species occur. ''Z. diploperennis'' and ''Z. perennis'' are perennial, while all other species are annual. All species are [[diploid]] (n=10) with the exception of ''Z. perennis'', which is [[tetraploid]] (n=20). The different species and subspecies of teosinte can be readily distinguished based on morphological, cytogenetic, protein, and DNA differences and on geographic origin. The two perennials are [[sympatric]] and very similar and some consider them to be one species. What many consider to be the most puzzling teosinte is ''Z. m. huehuetenangensis'', which combines a morphology rather like ''Z. m. parviglumis'' with many terminal chromosome knobs and an isozyme position between the two sections. Considered to be phenotypically the most distinctive, as well as the most threatened, teosinte is ''Zea nicaraguensis''. This teosinte thrives in flooded conditions along 200 m of a coastal estuarine river in northwest Nicaragua.

Teosintes strongly resemble maize in many ways, notably their tassel (male inflorescence) morphology. Teosintes are distinguished from maize most obviously by their numerous branches each bearing bunches of distinctive, small female [[inflorescences]]. These spikes mature to form a two-ranked 'ear' of five to 10 triangular or trapezoidal, black or brown disarticulating segments, each with one seed. Each seed is enclosed by a very hard fruitcase, consisting of a cupule or depression in the rachis and a tough lower glume. This protects them from the digestive processes of [[ruminants]] that forage on teosinte and aid in seed distribution through their droppings. Teosinte seed exhibits some resistance to germination, but will quickly [[germinate]] if treated with a dilute solution of hydrogen peroxide.{{Cn|date=February 2025}}

==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 />

==Ecology==
''Zea'' species are used as food plants by the [[larva]]e ([[caterpillar]]s) of some [[Lepidoptera]]n species including (in the Americas) the [[fall armyworm]] (''Spodoptera frugiperda''), the corn earworm (''[[Helicoverpa zea]]''), and the stem borers ''[[Diatraea]]'' and ''[[Chilo (moth)|Chilo]]''; in the Old World, it is attacked by the [[double-striped pug]], the cutworms [[heart and club]] and [[heart and dart]], ''[[Hypercompe indecisa]]'', the [[rustic shoulder-knot]], the [[setaceous Hebrew character]] and [[turnip moth]]s, and the [[European corn borer]] (''Ostrinia nubilalis''), among many others.

Virtually all populations of teosintes are either threatened or endangered: ''Z. diploperennis'' exists in an area of only a few square miles; ''Z. nicaraguensis'' survives as about 6000 plants in an area of 200 × 150&nbsp;m. The Mexican and Nicaraguan governments have taken action in recent years to protect wild teosinte populations, using both ''[[in situ]]'' and ''[[ex situ]]'' conservation methods. Currently, a large amount of scientific interest exists in conferring beneficial teosinte traits, such as nitrogen fixation,<ref name="PLOS_NitroFix">{{cite journal |last1=Van Deynze |first1=Allen |last2=Zamora |first2=Pablo |last3=Delaux |first3=Pierre-Marc |last4=Heitmann |first4=Cristobal |last5=Jayaraman |first5=Dhileepkumar |last6=Rajasekar |first6=Shanmugam |last7=Graham |first7=Danielle |last8=Maeda |first8=Junko |last9=Gibson |first9=Donald |last10=Schwartz |first10=Kevin D. |last11=Berry |first11=Alison M. |last12=Bhatnagar |first12=Srijak |last13=Jospin |first13=Guillaume |last14=Darling |first14=Aaron |last15=Jeannotte |first15=Richard |last16=Lopez |first16=Javier |last17=Weimer |first17=Bart C. |last18=Eisen |first18=Jonathan A. |last19=Shapiro |first19=Howard-Yana |last20=Ané |first20=Jean-Michel |last21=Bennett |first21=Alan B. |title=Nitrogen fixation in a landrace of maize is supported by a mucilage-associated diazotrophic microbiota |journal=[[PLOS Biology]]|date=7 August 2018 |volume=16 |issue=8 |pages=e2006352 |doi=10.1371/journal.pbio.2006352 |pmid=30086128 |pmc=6080747 |doi-access=free }}</ref> insect resistance, perennialism, and flood tolerance, to cultivated maize lines, although this is very difficult due to linked deleterious teosinte traits.{{Cn|date=February 2025}}

==Genomics==
[[Gene flow]] from [[genetically modified maize]] to teosinte weeds has only been observed to produce a GM teosinte with the same trait but this may not always be the outcome.<ref name="Risk-Assessment"/> Teosinte with a different insertion of the [[transgene]] may result and functionally different outcomes may be produced.<ref name="Risk-Assessment">
:{{Cite journal|issue=1|year=2020|publisher=[[Springer Science and Business Media LLC]]|volume=32|last1=Bauer-Panskus|first1=Andreas|last2=Miyazaki|first2=Juliana|last3=Kawall|first3=Katharina|last4=Then|first4=Christoph|journal=[[Environmental Sciences Europe]]|issn=2190-4707|s2cid=211540730|doi=10.1186/s12302-020-00301-0|title=Risk assessment of genetically engineered plants that can persist and propagate in the environment|doi-access=free}}
:
:This review cites this research.
:
{{Cite journal |year=2018 |publisher=[[Elsevier BV]] |pages=19–27 |last1=Devos |first1=Yann |last2=Ortiz-García |first2=Sol |last3=Hokanson |first3=Karen E. |last4=Raybould |first4=Alan |volume=259 |journal=[[Agriculture, Ecosystems & Environment]] |issn=0167-8809 |s2cid=90341111 |doi=10.1016/j.agee.2018.02.032 |title=Teosinte and maize × teosinte hybrid plants in Europe−Environmental risk assessment and management implications for genetically modified maize}}
</ref>

==References==
{{Reflist}}

==External links==
{{Commons category|Zea|<br />Zea (genus)}}
* {{cite news |last1=Carroll |first1=Sean B. |title=Tracking the Ancestry of Corn Back 9,000 Years |url=https://www.nytimes.com/2010/05/25/science/25creature.html |work=The New York Times |date=24 May 2010 }}

{{Taxonbar|from=Q542456}}
{{Authority control}}

[[Category:Zea (plant)| ]]
[[Category:Grasses of North America]]
[[Category:Grasses of South America]]
[[Category:Agriculture in Mesoamerica]]
[[Category:Crops originating from North America]]
[[Category:Crops originating from South America]]
[[Category:Crops originating from Pre-Columbian North America]]
[[Category:Poaceae genera|Zea]]
[[Category:Taxa named by Carl Linnaeus]]
[[Category:Andropogoneae]]