Editing Apomixis (section)

== Related terms ==
* '''Apomeiosis''': "Without meiosis"; usually meaning the production of a meiotically unreduced gametophyte.
* '''Parthenogenesis''': Development of an embryo directly from an egg cell without fertilization is called parthenogenesis. It is of two types:
**'''Haploid parthenogenesis''': Parthenogenesis of a normal [[haploid]] egg (a meiotically reduced egg) into an embryo is termed haploid parthenogenesis. If the mother plant was diploid, then the haploid embryo that results is [[monoploid]], and the plant that grows from the embryo is sterile. If they are not sterile, they are sometimes useful to plant breeders (especially in potato breeding, see [[ploidy#Dihaploidy and polyhaploidy|dihaploidy]]). This type of apomixis has been recorded in ''[[Solanum nigrum]]'', ''[[Lilium]]'' spp., ''[[Orchis maculata]]'', ''[[Nicotiana tabacum]]'', etc.
**'''Diploid parthenogenesis''': When the megagametophyte develops without completing meiosis, so that the megagametophyte and all cells within it are meiotically unreduced (a.k.a. diploid, but diploid is an ambiguous term), this is called diploid parthenogenesis, and the plant that develops from the embryo will have the same number of chromosomes as the mother plant. Diploid parthenogenesis is a component process of '''gametophytic apomixis''' (see above).
*{{anchor|Androgenesis}} '''Androgenesis''' and '''androclinesis''' are synonyms. These terms are used for two different processes that both have the effect of producing an embryo that has "male inheritance".
:The first process is a natural one. It may also be referred to as '''male apomixis''' or '''paternal apomixis'''. It involves fusion of the male and female gametes and replacement of the female nucleus by the male nucleus. This has been noted as a rare phenomenon in many plants (e.g. ''[[Nicotiana]]'' and ''[[Crepis]]''), and occurs as the regular reproductive method in the Saharan Cypress, ''[[Cupressus dupreziana]]''.<ref>{{cite journal |author1=Christian Pichot |author2=Benjamin Liens |author3=Juana L. Rivera Nava |author4=Julien B. Bachelier |author5=Mohamed El Maâtaoui |date=January 2008 |title=Cypress Surrogate Mother Produces Haploid Progeny From Alien Pollen |journal=Genetics|volume=178 |issue=1 |pages=379–383 |doi=10.1534/genetics.107.080572 |pmid=18202380 |pmc=2206086}}</ref><ref>{{cite journal|author1=Christian Pichot|author2=Bruno Fady|author3=Isabelle Hochu|year=2000|title=Lack of mother tree alleles in zymograms of ''Cupressus dupreziana'' A. Camus embryos|journal=Annals of Forest Science|volume=57|issue=1 |pages=17–22|doi=10.1051/forest:2000108|bibcode=2000AnFSc..57...17P |doi-access=free}}</ref><ref>{{cite journal|author1=Pichot, C. |author2=El Maataoui, M. |author3=Raddi, S. |author4=Raddi, P. |year=2001|title=Conservation: Surrogate mother for endangered ''Cupressus''|journal=Nature|volume=412|issue=6842|pages=39|doi=10.1038/35083687|pmid=11452293 |s2cid=39046191 |doi-access=free}}</ref> Recently, the first example of natural androgenesis in a vertebrate, a fish, [[Squalius alburnoides]] was discovered.<ref>{{cite journal |last1=Morgado-Santos |first1=Miguel |last2=Carona |first2=Sara |last3=Vicente |first3=Luís |last4=Collares-Pereira |first4=Maria João |title=First empirical evidence of naturally occurring androgenesis in vertebrates |journal=Royal Society Open Science |year=2017 |volume=4 |issue=5 |pages=170200 |doi=10.1098/rsos.170200 |pmid=28573029 |pmc=5451830 |bibcode=2017RSOS....470200M |doi-access=free }}</ref> It is also known in invertebrates, particularly clams in the genus ''[[Corbicula]]'', and these asexually reproducing males are noted to have a wider range than their noninvasive non-hermaphroditic cousins, more similar to hermaphroditic invasive species in the genus, indicating that this does sometimes have evolutionary benefits.<ref>{{cite journal |last1=Pigneur |first1=L.-M. |last2=Hedtke |first2=S. M. |last3=Etoundi |first3=E. |last4=Van Doninck |first4=K. |title=Androgenesis: a review through the study of the selfish shellfish Corbicula spp |journal=Heredity |date=June 2012 |volume=108 |issue=6 |pages=581–591 |doi=10.1038/hdy.2012.3 |pmid=22473310 |pmc=3356815 |issn=1365-2540|doi-access=free }}</ref>
:The second process that is referred to as androgenesis or androclinesis involves (artificial) culture of haploid plants from [[anther]] tissue or [[microspores]].<ref name=Solnzeva>{{cite journal | last1 = Solntzeva | first1 = M.P. | year = 2003 | title = About some terms of apomixis: pseudogamy and androgenesis | journal = Biologia | volume = 58 | issue = 1| pages = 1–7 }}</ref> Androgenesis has also been artificially induced in fish.<ref>{{cite journal |last1=Grunina |first1=A. S. |last2=Recoubratsky |first2=A. V. |title=Induced Androgenesis in Fish: Obtaining Viable Nucleocytoplasmic Hybrids |journal=Russian Journal of Developmental Biology |date=1 July 2005 |volume=36 |issue=4 |pages=208–217 |doi=10.1007/s11174-005-0035-5 |pmid=16208936 |s2cid=11750658 |url=https://link.springer.com/article/10.1007/s11174-005-0035-5 |language=en |issn=1608-3326}}</ref>
*'''Apogamy''': Although this term was (before 1908) used for other types of apomixis, and then discarded as too confusing, it is still sometimes used when an embryo develops from a cell of the megagametophyte other than the egg cell. In flowering plants, the cells involved in apogamy would be synergids or antipodal cells.
*'''Addition hybrids''', called '''B<sub>III</sub> hybrids''' by Rutishauser:<ref name=Rutishauser/> An embryo is formed after a meiotically unreduced egg cell is fertilized. The ploidy level of the embryo is therefore higher than that of the mother plant. This process occurs in some plants that are otherwise apomictic, and may play a significant role in producing tetraploid plants from triploid apomictic mother plants (if they receive pollen from diploids). Because fertilization is involved, this process does not fit the definition of apomixis.
*'''[[Pseudogamy]]''' refers to any reproductive process that requires [[pollination]] but does not involve male inheritance. It is sometimes used in a restrictive sense to refer to types of apomixis in which the [[endosperm]] is fertilized but the [[embryo]] is not. A better term for the restrictive sense is '''centrogamy'''.<ref name=Solnzeva/>
*'''Agamospecies''', the concept introduced by [[Göte Turesson]]: "an apomict population the constituents of which, for morphological, cytological or other reasons, are to be considered as having a common origin," i.e., basically synonymous with "microspecies.<ref>Defining species: a sourcebook from antiquity to today, by John S. Wilkins, {{ISBN|1433102161}}, 2009, [https://books.google.com/books?id=pazpr2vJxQAC&dq=agamospecies&pg=PA194 pp. 122, 194]</ref>