Zea (plant)
Zea | |
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Zea mays
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Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Monocots |
Clade: | Commelinids |
Order: | Poales |
Family: | Poaceae |
Subfamily: | Panicoideae |
Supertribe: | Andropogonodae |
Tribe: | Andropogoneae |
Subtribe: | Tripsacinae |
Genus: | Zea L. |
Type species | |
Zea mays
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Synonyms[1] | |
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Zea is a genus of flowering plants in the 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 name (ζειά) for another cereal grain (possibly spelt).[2]
Recognized species
The five accepted species names in the genus are:[3][4]
Ear | Plant | Scientific name | Common Name | Distribution |
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Zea diploperennis H.H.Iltis et al. | diploperennial teosinte | Jalisco | ||
Zea luxurians (Durieu & Asch.) R.M.Bird | Maíz de Monte, Florida teosinte and Guatemalan teosinte | Chiapas, Guatemala, Honduras | ||
Zea mays L. |
Corn, Maize | southern Mexico, Guatemala; cultivated in many places | ||
Zea nicaraguensis H.H.Iltis & B.F.Benz | Nicaraguan teosinte | Nicaragua | ||
Zea perennis (Hitchc.) Reeves & Mangelsd. | perennial teosinte | Jalisco |
The genus is divided into two 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]
Description
Both
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
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.[5]
(Part of Poaceae) |
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Teosintes are critical components of
All but the Nicaraguan 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 plant, and encourage its introgression into their maize.
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."[6]
Ecology
Zea species are used as food plants by the
(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 m. The Mexican and Nicaraguan governments have taken action in recent years to protect wild teosinte populations, using both
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.[9] Teosinte with a different insertion of the transgene may result and functionally different outcomes may be produced.[9]
References
- ^ Kew World Checklist of Selected Plant Families
- ISBN 9780521685535(paperback). pp 411
- ^ "ITIS - Report: Zea".
- ^ S2CID 8045294.
- PMID 10860964.
- ^ PMID 11983901.
- PMID 23671421.
- PMID 30086128.
- ^ a b
- Bauer-Panskus, Andreas; Miyazaki, Juliana; Kawall, Katharina; Then, Christoph (2020). "Risk assessment of genetically engineered plants that can persist and propagate in the environment". S2CID 211540730.
- This review cites this research.
S2CID 90341111. - Bauer-Panskus, Andreas; Miyazaki, Juliana; Kawall, Katharina; Then, Christoph (2020). "Risk assessment of genetically engineered plants that can persist and propagate in the environment".
External links
Zea (genus).
- Carroll, Sean B. (24 May 2010). "Tracking the Ancestry of Corn Back 9,000 Years". The New York Times.