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Gossypium

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"Cotton plant" redirects here. For the city in the United States, seeCotton Plant, Arkansas.
For information on cotton production, industry, history, and applications, seecotton.

Gossypium
Flower ofGossypium herbaceum
Scientific classificationEdit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Malvales
Family: Malvaceae
Subfamily: Malvoideae
Tribe: Gossypieae
Genus: Gossypium
L.[1]
Type species
Gossypium arboreum
Species

See text.

Synonyms[1]
  • ErioxylumRose & Standl.
  • IngenhouziaDC.
  • NotoxylinonLewton
  • SeleraUlbr.
  • SturtiaR.Br.
  • ThurberiaA.Gray
  • UltragossypiumRoberty

Gossypium(/ɡɒˈsɪpiəm/)[2]is agenusofflowering plantsin the tribeGossypieaeof themallowfamily,Malvaceae,from whichcottonis harvested. It is native to tropical and subtropical regions of theOldandNew Worlds.There are about 50Gossypiumspecies,[3]making it the largest genus in the tribe Gossypieae, and new species continue to be discovered.[3]The name of the genus is derived from the Arabic wordgoz,which refers to a soft substance.[4]

Cotton is the primarynatural fibreused by humans today, amounting to about 80% of world natural fibre production.[5]Where cotton is cultivated, it is a major oilseed crop and a main protein source for animal feed. Cotton is thus of great importance for agriculture, industry and trade, especially fortropicalandsubtropicalcountries in Africa, South America and Asia. Consequently, the genusGossypiumhas long attracted the attention of scientists.

The origin of the genusGossypiumis dated to around 5–10 million years ago.[6]Gossypiumspecies are distributed inaridtosemiaridregions of the tropics and subtropics. Generallyshrubsor shrub-like plants, the species of this genus are extraordinarily diverse inmorphologyandadaptation,ranging from fire-adapted,herbaceousperennialsin Australia to trees in Mexico.[3]Most wild cottons arediploid,but a group of five species from America and Pacific islands are tetraploid, apparently due to a single hybridization event around 1.5 to 2 million years ago.[6]The tetraploid species areG. hirsutum,G. tomentosum,G. mustelinum,G. barbadense,andG. darwinii.

Cultivated cottons are perennial shrubs, most often grown as annuals. Plants are 1–2 m high in modern cropping systems, sometimes higher in traditional, multiannual cropping systems, now largely disappearing. The leaves are broad and lobed, with three to five (or rarely seven) lobes. The seeds are contained in acapsulecalled a "boll", each seed surrounded by fibres of two types. These fibres are the more commercially interesting part of the plant and they are separated from the seed by a process calledginning.At the first ginning, the longer fibres, called staples, are removed and these are twisted together to form yarn for making thread and weaving into high quality textiles. At the second ginning, the shorter fibres, called "linters", are removed, and these are woven into lower quality textiles (which include the eponymouslint). Commercial species of cotton plant areG. hirsutum(97% of world production),G. barbadense(1–2%),G. arboreumandG. herbaceum(together, ~1%).[7]Many varieties of cotton have been developed by selective breeding and hybridization of these species. Experiments are ongoing to cross-breed various desirable traits of wild cotton species into the principal commercial species, such as resistance to insects and diseases, and drought tolerance. Cotton fibres occur naturally in colours of white, brown, green, and some mi xing of these.

Selected species

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SubgenusGossypium

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SubgenusHouzingenia

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SubgenusKarpas

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SubgenusSturtia

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Formerly placed in genusGossypium

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Gossypiumgenome

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A public genome sequencing effort of cotton was initiated[10]in 2007 by a consortium of public researchers. They agreed on a strategy to sequence the genome of cultivated,allotetraploidcotton. "Allotetraploid" means that the genomes of these cotton species comprise two distinct subgenomes, referred to as the At and Dt (the 't' for tetraploid, to distinguish them from the A and D genomes of the related diploid species). The strategy is to sequence first the D-genome relative of allotetraploid cottons,G. raimondii,a wild South American (Peru,Ecuador) cotton species, because of its smaller size due essentially to less repetitive DNA (retrotransposons mainly). It has nearly one-third the number of bases of tetraploid cotton (AD), and each chromosome is only present once.[clarification needed]The A genome ofG. arboreum,the 'Old-World' cotton species (grown in India in particular), would be sequenced next. Its genome is roughly twice the size ofG. raimondii's. Once both A and D genome sequences are assembled, then research could begin to sequence the actual genomes of tetraploid cultivated cotton varieties. This strategy is out of necessity; if one were to sequence the tetraploid genome without model diploid genomes, the euchromatic DNA sequences of the AD genomes would co-assemble and the repetitive elements of AD genomes would assemble independently into A and D sequences, respectively. Then there would be no way to untangle the mess of AD sequences without comparing them to their diploid counterparts.

The public sector effort continues with the goal to create a high-quality, draft genome sequence from reads generated by all sources. The public-sector effort has generated Sanger reads of BACs, fosmids, and plasmids, as well as 454 reads. These later types of reads will be instrumental in assembling an initial draft of the D genome. In 2010, two companies (MonsantoandIllumina), completed enough Illumina sequencing to cover the D genome ofG. raimondiiabout 50x.[11]They announced they would donate their raw reads to the public. This public relations effort gave them some recognition for sequencing the cotton genome. Once the D genome is assembled from all of this raw material, it will undoubtedly assist in the assembly of the AD genomes of cultivated varieties of cotton, but a lot of hard work remains.

Cotton pests and diseases

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Cotton field inSukhumi Botanical Garden,photocirca1912
Cotton field inGreece

Pests

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Diseases

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See also:List of cotton diseases
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See also

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References

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  1. ^ab"Genus:GossypiumL ".Germplasm Resources Information Network.United States Department of Agriculture. 2007-03-12. Archived fromthe originalon 2011-07-17.Retrieved2011-09-08.
  2. ^"Gossypium".Merriam-Webster Dictionary.Merriam-Webster.Retrieved2020-05-19.
  3. ^abcWendel JF, Brubaker C, Alvarez I, et al. (2009). "Evolution and Natural History of the Cotton Genus". In Andrew H. Paterson (ed.).Plant Genetics and Genomics: Crops and Models.Vol. 3. pp. 3–22.doi:10.1007/978-0-387-70810-2_1.ISBN978-0-387-70809-6.
  4. ^Gledhill, D. (2008).The Names of Plants(4 ed.). Cambridge University Press. p. 182.ISBN978-0-521-86645-3.
  5. ^Townsend, Terry (2020). "1B - World natural fibre production and employment".Handbook of Natural Fibres.Vol. 1 (2 ed.). Woodhead Publishing. pp. 15–36.doi:10.1016/B978-0-12-818398-4.00002-5.ISBN9780128183984.S2CID212822506.
  6. ^abSenchina DS, Alvarez I, Cronn RC, et al. (2003)."Rate variation among nuclear genes and the age of polyploidy in Gossypium".Mol. Biol. Evol.20(4): 633–643.doi:10.1093/molbev/msg065.PMID12679546.
  7. ^Chaudhry, M. R. (2010). "10 - Cotton Production and Processing".Industrial Applications of Natural Fibres.John Wiley & Sons, Ltd. pp. 219–234.doi:10.1002/9780470660324.ch10.ISBN9780470660324.
  8. ^"Gossypium".Integrated Taxonomic Information System.Retrieved2011-09-08.
  9. ^ab"GRIN Species Records ofGossypium".Germplasm Resources Information Network.United States Department of Agriculture. Archived fromthe originalon 2015-09-24.Retrieved2011-09-08.
  10. ^Chen ZJ, Scheffler BE, Dennis E, et al. (Dec 2007)."Toward sequencing cotton (Gossypium) genomes".Plant Physiol.145(4): 1303–10.doi:10.1104/pp.107.107672.PMC2151711.PMID18056866.
  11. ^APPDMZ\gyoung."Monsanto and Illumina Reach Key Milestone in Cotton Genome Sequencing".monsanto.Archived fromthe originalon 2016-02-01.Retrieved2016-01-31.
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