Editing Wheat (section)

=== Phylogeny ===

[[File:Polyploid wheat origins.svg|thumb|upright=2.5|Wheat origins by repeated [[Hybrid (biology)|hybridization]] and [[polyploidy]].<ref name="Golovnina-2007"/> Not all species are shown.]]

Some wheat species are [[diploid]], with two sets of [[chromosome]]s, but many are stable [[polyploidy|polyploids]], with four sets of chromosomes ([[tetraploid]]) or six ([[hexaploid]]).<ref name="Golovnina-2007"/> [[Einkorn]] wheat (''Triticum monococcum'') is diploid (AA, two complements of seven chromosomes, 2n=14).<ref name="Belderok-2000"/> Most tetraploid wheats (e.g. [[emmer]] and [[durum]] wheat) are derived from [[Emmer#Wild emmer|wild emmer]], ''T. dicoccoides''. Wild emmer is itself the result of a hybridization between two diploid wild grasses, ''[[Triticum urartu|T. urartu]]'' and a wild goatgrass such as ''[[Aegilops speltoides|Ae. speltoides]]''.<ref>{{cite journal |last1=Friebe |first1=B. |last2=Qi |first2=L.L. |last3=Nasuda |first3=S. |last4=Zhang |first4=P. |last5=Tuleen |first5=N.A. |last6=Gill |first6=B.S. |s2cid=13010134 |title=Development of a complete set of ''Triticum aestivum''-''Aegilops speltoides'' chromosome addition lines |journal=[[Theoretical and Applied Genetics]] |date=July 2000 |volume=101 |issue=1 |pages=51–58 |doi=10.1007/s001220051448}}</ref> The hybridization that formed wild emmer (AABB, four complements of seven chromosomes in two groups, 4n=28) occurred in the wild, long before domestication, and was driven by [[natural selection]]. Hexaploid wheats evolved in farmers' fields as wild emmer hybridized with another goatgrass, ''[[Aegilops squarrosa|Ae. squarrosa]]'' or ''[[Aegilops tauschii|Ae. tauschii]]'', to make the [[hexaploid]] wheats including [[common wheat|bread wheat]].<ref name="Golovnina-2007"/><ref name="Dvorak-2012">{{Cite journal |last1=Dvorak |first1=Jan |last2=Deal |first2=Karin R. |last3=Luo |first3=Ming-Cheng |last4=You |first4=Frank M. |last5=von Borstel |first5=Keith |last6=Dehghani |first6=Hamid |date=2012-05-01 |title=The Origin of Spelt and Free-Threshing Hexaploid Wheat |journal=[[Journal of Heredity]] |volume=103 |issue=3 |pages=426–441 |doi=10.1093/jhered/esr152 |pmid=22378960 |doi-access=free}}</ref>

A 2007 [[Molecular phylogenetics|molecular phylogeny]] of the wheats gives the following not fully-resolved [[cladogram]] of major cultivated species; the large amount of hybridisation makes resolution difficult. Markings like "6N" indicate the degree of [[polyploidy]] of each species:<ref name="Golovnina-2007">{{cite journal |last1=Golovnina |first1=K. A. |last2=Glushkov |first2=S. A. |last3=Blinov |first3=A. G. |last4=Mayorov |first4=V. I. |last5=Adkison |first5=L. R. |last6=Goncharov |first6=N. P. |title=Molecular phylogeny of the genus Triticum L |journal=Plant Systematics and Evolution |publisher=Springer |volume=264 |issue=3–4 |date=2007-02-12 |doi=10.1007/s00606-006-0478-x |pages=195–216|bibcode=2007PSyEv.264..195G |s2cid=39102602 }}</ref>

{{clade
|label1=[[Triticeae]]
|1={{clade
   |1=[[Barley]] 2N, [[rye]] 2N/4N, and other cereals
   |label2='''Wheats'''
   |2={{clade
      |1={{clade
         |1=''Triticum monococcum'' ([[Einkorn wheat|einkorn]]) 2N
         |2=''[[× Aegilotriticum]]'' hybrids (''[[Aegilops]]'' x ''Triticum'') 6N
         }}
      |2={{clade
         |1= ''[[Triticum timopheevii]]'' (zanduri wheat) and others 4N
         |2={{clade
            |1=''Triticum aestivum'' ([[Common wheat|common or bread wheat]]) 6N
            |2=''Triticum durum/turgidum'' ([[durum]] wheat) 4N
            |3=''Triticum spelta'' ([[spelt]]) 6N
            |4=''Triticum turanicum'' ([[khorasan wheat]]) 4N
            |5=''Triticum dicoccum'' ([[emmer]]) 4N
            |6= many other species
            }}
         }}
      }}
   }}
}}