Editing Ploidy (section)

===Dihaploidy and polyhaploidy===
{{distinguish |text=[[Haplodiploid sex-determination system|haplodiploidy]] (where diploid and haploid individuals are different sexes)}}
Dihaploid and polyhaploid cells are formed by [[haploidisation]] of polyploids, i.e., by halving the chromosome constitution.{{citation needed|date=May 2023}}

Dihaploids (which are diploid) are important for selective breeding of tetraploid crop plants (notably potatoes), because selection is faster with diploids than with tetraploids. Tetraploids can be reconstituted from the diploids, for example by somatic fusion.{{citation needed|date=May 2023}}

The term "dihaploid" was coined by Bender<ref>{{cite journal | author=Bender K | year=1963 | title=Über die Erzeugung und Entstehung dihaploider Pflanzen bei ''Solanum tuberosum''". | journal=Zeitschrift für Pflanzenzüchtung | volume=50 | pages=141–166 }}</ref> to combine in one word the number of genome copies (diploid) and their origin (haploid). The term is well established in this original sense,<ref>Nogler, G.A. 1984. Gametophytic apomixis. In ''Embryology of angiosperms''. Edited by B.M. Johri. Springer, Berlin, Germany. pp. 475–518.</ref><ref>* {{cite journal | author=Pehu E | year=1996 | title=The current status of knowledge on the cellular biology of potato | journal=Potato Research | volume=39 | issue= 3| pages=429–435 | doi=10.1007/bf02357948| s2cid=32122774 }}</ref> but it has also been used for doubled monoploids or [[doubled haploidy|doubled haploids]], which are homozygous and used for genetic research.<ref>* {{cite journal |author1=Sprague G.F. |author2=Russell W.A. |author3=Penny L.H. | year=1960 | title=Mutations affecting quantitative traits in the selfed progeny of double monoploid maize stocks | journal=Genetics | volume=45 | issue=7 | pages=855–866 |doi=10.1093/genetics/45.7.855 |pmid=17247970 |pmc=1210096 }}</ref>