dioecy#In botany

File:Physalia.jpg, is a dioecious colonial marine animal; the reproductive medusae within the colony are all of the same sex.{{cite web |url=http://animaldiversity.ummz.umich.edu/accounts/Physalia_physalis/ |title=Animal Diversity Web |access-date=27 April 2014}}]]

{{Further|Gonochorism}}

In zoology, dioecy means that an animal is either male or female, in which case the synonym gonochory is more often used.{{Page needed|date=August 2021}} Most animal species are gonochoric, almost all vertebrate species are gonochoric, and all bird and mammal species are gonochoric.{{cite journal|author=David, J.R.|year=2001|title=Evolution and development: some insights from evolutionary theory|journal=Anais da Academia Brasileira de Ciências|volume=73|issue=3|pages=385–395|doi=10.1590/s0001-37652001000300008|pmid=11600899|doi-access=free}} Dioecy may also describe colonies within an animal species, such as the colonies of Siphonophorae (Portuguese man-of-war), which may be either dioecious or monoecious.{{cite journal |author1=Dunn, C.W. |author2=Pugh, P.R. |author3=Haddock, S.H.D. |author3-link=Steven Haddock |year=2005 |title=Molecular Phylogenetics of the Siphonophora (Cnidaria), with Implications for the Evolution of Functional Specialization |journal=Systematic Biology |volume=54 |issue=6 |pages=916–935 |doi=10.1080/10635150500354837 |pmid=16338764|doi-access= }}

Land plants (embryophytes) differ from animals in that their life cycle involves alternation of generations. In animals, typically an individual produces gametes of one kind, either sperm or egg cells. The gametes have half the number of chromosomes of the individual producing them, so are haploid. Without further dividing, a sperm and an egg cell fuse to form a zygote that develops into a new individual. In land plants, by contrast, one generation – the sporophyte generation – consists of individuals that produce haploid spores rather than haploid gametes. Spores do not fuse, but germinate by dividing repeatedly by mitosis to give rise to haploid multicellular individuals, the gametophytes, which produce gametes. A male gamete and a female gamete then fuse to produce a new diploid sporophyte.{{sfnp|Mauseth|2014|pp=204–205}}

File:Alternation of generations simpler still.svg

In bryophytes (mosses, liverworts and hornworts), the gametophytes are fully independent plants.{{sfnp|Mauseth|2014|p=487}} Seed plant gametophytes are dependent on the sporophyte and develop within the spores, a condition known as endospory. In flowering plants, the male gametophytes develop within pollen grains produced by the sporophyte's stamens, and the female gametophytes develop within ovules produced by the sporophyte's carpels.{{sfnp|Mauseth|2014|pp=204–205}}

The sporophyte generation of a seed plant is called "monoecious" when each sporophyte plant has both kinds of spore-producing organ but in separate flowers or cones. For example, a single flowering plant of a monoecious species has both functional stamens and carpels, in separate flowers.{{sfnp|Mauseth|2014|p=218}}

The sporophyte generation of seed plants is called dioecious when each sporophyte plant has only one kind of spore-producing organ, all of whose spores give rise either to male gametophytes, which produce only male gametes (sperm), or to female gametophytes, which produce only female gametes (egg cells). For example, a single flowering plant sporophyte of a fully dioecious species like holly has either flowers with functional stamens producing pollen containing male gametes (staminate or 'male' flowers), or flowers with functional carpels producing female gametes (carpellate or 'female' flowers), but not both.{{sfnp|Mauseth|2014|p=218}}{{Cite book |last1=Hickey |first1=M. |last2=King |first2=C. |year=2001 |title=The Cambridge Illustrated Glossary of Botanical Terms |publisher=Cambridge University Press |name-list-style=amp}} There are other, more complex reproductive schemes such as gynodioecy and androdioecy.

Ilex aquifolium male HC1.JPG|In dioecious holly, some plants only have 'male' flowers with stamens producing pollen.

Ilex aquifolium female HC1.JPG|Other holly plants only have 'female' flowers that produce ovules.

Tulip Tulipa clusiana 'Lady Jane' Rock Ledge Flower 2000px.jpg|Each bisexual (perfect) tulip flower has both stamens and carpels.

Slightly different terms, dioicous and monoicous, may be used for the gametophyte generation of non-vascular plants, although dioecious and monoecious are also used.{{Cite web |last1=Lepp |first1=Heino |date=2007 |title=Case studies : -oicy : Dioicous, dioecious, monoicous and monoecious |website=Australian Bryophytes |publisher=Australian National Botanic Gardens and Australian National Herbarium |url=https://www.anbg.gov.au/bryophyte/case-studies/-oicy.html |access-date=2021-06-21 }}{{cite book|author=Stearn, W.T.|year=1992|title=Botanical Latin: History, grammar, syntax, terminology and vocabulary, Fourth edition|publisher=David and Charles}} A dioicous gametophyte either produces only male gametes (sperm) or produces only female gametes (egg cells). About 60% of liverworts are dioicous.{{cite book |vauthors=Vanderpoorten A,Goffinet B |date=2009 |title=Introduction to bryophytes |chapter=Liverworts |publisher=Cambridge University Press |location=Cambridge, UK |isbn=978-0-521-70073-3 }}{{rp|52}}

Dioecy occurs in a wide variety of plant groups. Examples of dioecious plant species include ginkgos, willows, cannabis and African teak. As its specific name implies, the perennial stinging nettle Urtica dioica is dioecious,{{cite book|last=Stace|first=C. A.|author-link = Stace, C. A.|year=2019|title=New Flora of the British Isles|edition=Fourth|publisher=C & M Floristics|location = Middlewood Green, Suffolk, U.K.| isbn=978-1-5272-2630-2}}{{rp|305}} while the annual nettle Urtica urens is monoecious.{{rp|305}} Dioecious flora are predominant in tropical environments.{{Cite book|last1=Tandon|first1=Rajesh|url=https://books.google.com/books?id=WED2DwAAQBAJ&q=dioecy+tropical+climates&pg=PA179|title=Reproductive Ecology of Flowering Plants: Patterns and Processes|last2=Shivanna|first2=K. R.|last3=Koul|first3=Monika|date=2020-08-07|publisher=Springer Nature|isbn=978-981-15-4210-7|pages=179|language=en}}

About 65% of gymnosperm species are dioecious,{{Cite journal|date=2018-09-01|title=Sexual systems in gymnosperms: A review|url=https://www.sciencedirect.com/science/article/abs/pii/S1439179117304498|journal=Basic and Applied Ecology|language=en|volume=31|pages=1–9|doi=10.1016/j.baae.2018.05.009|issn=1439-1791|last1=Walas|first1=Łukasz|last2=Mandryk|first2=Wojciech|last3=Thomas|first3=Peter A.|last4=Tyrała-Wierucka|first4=Żanna|last5=Iszkuło|first5=Grzegorz|bibcode=2018BApEc..31....1W |s2cid=90740232}} but almost all conifers are monoecious.{{cite journal| vauthors = Walas Ł, Mandryk W, Thomas PA, Tyrała-Wierucka Ż, Iszkuło G |date=2018|title=Sexual systems in gymnosperms: A review|journal=Basic and Applied Ecology|volume=31|pages=1–9|doi=10.1016/j.baae.2018.05.009|bibcode=2018BApEc..31....1W |s2cid=90740232|url=http://eprints.keele.ac.uk/4961/1/29052018_1-s2.0-S1439179117304498-main.pdf}}

In gymnosperms, the sexual systems dioecy and monoecy are strongly correlated with the mode of pollen dispersal, monoecious species are predominantly wind dispersed (anemophily) and dioecious species animal-dispersed (zoophily).{{cite journal |author=Givnish, TJ |date=1980 |title=Ecological constraints on the evolution of breeding systems in seed plants: dioecy and dispersal in gymnosperms |journal=Evolution |volume=34 |issue=5 |pages=959–972 |doi=10.1111/j.1558-5646.1980.tb04034.x |pmid=28581147 |doi-access=free }}

About 6 percent of flowering plant species are entirely dioecious and about 7% of angiosperm genera contain some dioecious species.{{cite journal|author1=Renner, S. S. |author-link=Susanne Renner|author2=R. E. Ricklefs|year=1995|title=Dioecy and its correlates in the flowering plants|journal=American Journal of Botany|volume=82|issue=5|pages=596–606|doi=10.2307/2445418|jstor=2445418|url=https://epub.ub.uni-muenchen.de/14619/}} Dioecy is more common in woody plants,{{citation |author1=Matallana, G. |author2=Wendt, T. |author3=Araujo, D.S.D. |author4=Scarano, F.R. |year=2005 |title=High abundance of dioecious plants in a tropical coastal vegetation |journal=American Journal of Botany |volume=92 |issue=9 |pages=1513–1519 |doi=10.3732/ajb.92.9.1513 |pmid=21646169 }} and heterotrophic species.{{cite journal | author = Nickrent D.L., Musselman L.J. | year = 2004 | title = Introduction to Parasitic Flowering Plants | url = http://www.apsnet.org/edcenter/intropp/pathogengroups/pages/parasiticplants.aspx | journal = The Plant Health Instructor | doi = 10.1094/PHI-I-2004-0330-01 | access-date = 2017-01-10 | archive-url = https://web.archive.org/web/20161005194620/http://www.apsnet.org/edcenter/intropp/pathogengroups/pages/parasiticplants.aspx | archive-date = 2016-10-05 | url-status = dead }} In most dioecious plants, whether male or female gametophytes are produced is determined genetically, but in some cases it can be determined by the environment, as in Arisaema species.{{Cite book|last1=Fusco|first1=Giuseppe|url=https://books.google.com/books?id=AKGsDwAAQBAJ&q=gonochorism+sex+determination|title=The Biology of Reproduction|last2=Minelli|first2=Alessandro|date=2019-10-10|publisher=Cambridge University Press|isbn=978-1-108-49985-9|pages=329|language=en}}

Certain algae, such as some species of Polysiphonia, are dioecious.Maggs, C.A. and Hommersand, M.H. 1993. Seaweeds of the British Isles Volume 1 Rhodophyta Part 3A Ceramiales. The Natural History Museum, London. {{ISBN|0-11-310045-0}} Dioecy is prevalent in the brown algae (Phaeophyceae) and may have been the ancestral state in that group.{{cite journal |vauthors=LuthringerR, Cormier A, Ahmed S, Peters AF, Cock JM, Coelho, SM |title=Sexual dimorphism in the brown algae |journal=Perspectives in Phycology |volume=1 |date=2014 |issue=1 |pages=11–25 |doi=10.1127/2198-011X/2014/0002 }}

{{For|evolution in animals|Gonochorism#Evolution}}

In plants, dioecy has evolved independently multiple times{{Cite journal |last1=Bachtrog |first1=Doris |last2=Mank |first2=Judith E. |last3=Peichel |first3=Catherine L. |last4=Kirkpatrick |first4=Mark |last5=Otto |first5=Sarah P. |last6=Ashman |first6=Tia-Lynn |last7=Hahn |first7=Matthew W. |last8=Kitano |first8=Jun |last9=Mayrose |first9=Itay |last10=Ming |first10=Ray |last11=Perrin |first11=Nicolas |date=2014-07-01 |title=Sex Determination: Why So Many Ways of Doing It? |journal=PLOS Biology |volume=12 |issue=7 |pages=e1001899 |doi=10.1371/journal.pbio.1001899 |issn=1544-9173 |pmc=4077654 |pmid=24983465 |doi-access=free }} either from hermaphroditic species or from monoecious species. A previously untested hypothesis is that this reduces inbreeding;{{Cite journal |last1=Sarkar |first1=Sutanu |last2=Banerjee |first2=Joydeep |last3=Gantait |first3=Saikat|date=2017-05-29 |title=Sex-oriented research on dioecious crops of Indian subcontinent: an updated review|url=https://doi.org/10.1007/s13205-017-0723-8|journal=3 Biotech|language=en|volume=7|issue=2|pages=93|doi=10.1007/s13205-017-0723-8|issn=2190-5738|pmc=5447520|pmid=28555429}} dioecy has been shown to be associated with increased genetic diversity and greater protection against deleterious mutations.{{Cite journal |last1=Muyle|first1=Aline|last2=Martin |first2=Hélène|last3=Zemp|first3=Niklaus|last4=Mollion|first4=Maéva |last5=Gallina|first5=Sophie|last6=Tavares|first6=Raquel |last7=Silva|first7=Alexandre|last8=Bataillon|first8=Thomas|last9=Widmer |first9=Alex|last10=Glémin|first10=Sylvain |last11=Touzet|first11=Pascal |date=2021-03-01 |title=Dioecy Is Associated with High Genetic Diversity and Adaptation Rates in the Plant Genus Silene|url=https://doi.org/10.1093/molbev/msaa229 |journal=Molecular Biology and Evolution |volume=38 |issue=3 |pages=805–818|doi=10.1093/molbev/msaa229|issn=0737-4038|pmc=7947750|pmid=32926156}} Regardless of the evolutionary pathway the intermediate states need to have fitness advantages compared to cosexual flowers in order to survive.{{Cite book|last=Cruzan|first=Mitchell B.|url=https://books.google.com/books?id=nzRtDwAAQBAJ&q=Dioicy+sexual+system&pg=PA377|title=Evolutionary Biology: A Plant Perspective|date=2018-09-11|publisher=Oxford University Press|isbn=978-0-19-088268-6|pages=377|language=en}}

Dioecy evolves due to male or female sterility,{{Cite book|last1=Atwell|first1=Brian James|url=https://books.google.com/books?id=chWs4ewSzpEC&q=all+botanists+agree+dioecy&pg=PT49|title=Plants in Action: Adaptation in Nature, Performance in Cultivation|last2=Kriedemann|first2=Paul E.|last3=Turnbull|first3=Colin G. N.|date=1999|publisher=Macmillan Education AU|isbn=978-0-7329-4439-1|pages=249|language=en}} although it is unlikely that mutations for male and female sterility occurred at the same time.{{Cite book|last=Karasawa|first=Marines Marli Gniech|url=https://books.google.com/books?id=prsDCwAAQBAJ&q=evolution+Monoecy|title=Reproductive Diversity of Plants: An Evolutionary Perspective and Genetic Basis|date=2015-11-23|publisher=Springer|isbn=978-3-319-21254-8|pages=31|language=en}} In angiosperms unisexual flowers evolve from bisexual ones.{{Cite book|last1=Núñez-Farfán|first1=Juan|url=https://books.google.com/books?id=iF70DwAAQBAJ&q=dioecy+consensus&pg=PA177|title=Evolutionary Ecology of Plant-Herbivore Interaction|last2=Valverde|first2=Pedro Luis|date=2020-07-30|publisher=Springer Nature|isbn=978-3-030-46012-9|pages=177|language=en}} Dioecy occurs in almost half of plant families, but only in a minority of genera, suggesting recent evolution.{{Cite book|last=Reeve|first=Eric C. R.|url=https://books.google.com/books?id=PuCYAgAAQBAJ&q=evolution+of+dioecy&pg=PA616|title=Encyclopedia of Genetics|date=2014-01-14|publisher=Routledge|isbn=978-1-134-26350-9|pages=616|language=en}} For 160 families that have dioecious species, dioecy is thought to have evolved more than 100 times.{{Cite journal|last=Ainsworth|first=Charles|date=2000-08-01|title=Boys and Girls Come Out to Play: The Molecular Biology of Dioecious Plants|journal=Annals of Botany|volume=86|issue=2|pages=211–221|doi=10.1006/anbo.2000.1201|s2cid=85039623 |issn=0305-7364|doi-access=free}}

In the family Caricaceae, dioecy is likely the ancestral sexual system.{{Cite book|last=Mitra|first=Sisir|url=https://books.google.com/books?id=7zX8DwAAQBAJ&dq=trioecy&pg=PA161|title=The Papaya: Botany, Production and Uses|date=2020-09-01|publisher=CABI|isbn=978-1-78924-190-7|pages=161|language=en}}

Dioecious flowering plants can evolve from monoecious ancestors that have flowers containing both functional stamens and functional carpels. Some authors argue monoecy and dioecy are related.{{Cite book|last=Batygina|first=T. B.|url=https://books.google.com/books?id=4VOWDwAAQBAJ&q=monoecy&pg=PA43|title=Embryology of Flowering Plants: Terminology and Concepts, Vol. 3: Reproductive Systems|date=2019-04-23|publisher=CRC Press|isbn=978-1-4398-4436-6|pages=43|language=en}}

In the genus Sagittaria, since there is a distribution of sexual systems, it has been postulated that dioecy evolved from monoecy{{Cite book|last1=Wilson|first1=Karen L.|url=https://books.google.com/books?id=YzQBUQqLS0YC&q=Monoecy&pg=PA264|title=Monocots: Systematics and Evolution: Systematics and Evolution|last2=Morrison|first2=David A.|date=2000-05-19|publisher=Csiro Publishing|isbn=978-0-643-09929-6|pages=264|language=en}} through gynodioecy mainly from mutations that resulted in male sterility.{{Cite book|url=https://books.google.com/books?id=_r4OCAAAQBAJ&q=evolution+of+Monoecy&pg=RA1-PA478|title=Encyclopedia of Evolutionary Biology|date=2016-04-14|publisher=Academic Press|isbn=978-0-12-800426-5|volume=2|language=en}}{{rp|478}} However, since the ancestral state is unclear, more work is needed to clarify the evolution of dioecy via monoecy.{{rp|478}}

Dioecy usually evolves from hermaphroditism through gynodioecy but may also evolve through androdioecy,{{Cite journal|last1=Perry|first1=Laura E.|last2=Pannell|first2=John R.|last3=Dorken|first3=Marcel E.|date=2012-04-19|title=Two's Company, Three's a Crowd: Experimental Evaluation of the Evolutionary Maintenance of Trioecy in Mercurialis annua (Euphorbiaceae)|journal=PLOS ONE|language=en|volume=7|issue=4|pages=e35597|doi=10.1371/journal.pone.0035597|issn=1932-6203|pmc=3330815|pmid=22532862|bibcode=2012PLoSO...735597P |doi-access=free}} through distyly{{Cite book|last=Leonard|first=Janet L.|url=https://books.google.com/books?id=0rWZDwAAQBAJ&q=evolution+of+Monoecy&pg=PA91|title=Transitions Between Sexual Systems: Understanding the Mechanisms of, and Pathways Between, Dioecy, Hermaphroditism and Other Sexual Systems|date=2019-05-21|publisher=Springer|isbn=978-3-319-94139-4|pages=91|language=en}} or through heterostyly. In the Asteraceae, dioecy may have evolved independently from hermaphroditism at least 5 or 9 times. The reverse transition, from dioecy back to hermaphroditism has also been observed, both in Asteraceae and in bryophytes, with a frequency about half of that for the forward transition.{{Cite book|last1=Landry|first1=Christian R.|url=https://books.google.com/books?id=WATFBAAAQBAJ&q=Asteraceae+dioecy&pg=PA9|title=Ecological Genomics: Ecology and the Evolution of Genes and Genomes|last2=Aubin-Horth|first2=Nadia|date=2013-11-25|publisher=Springer Science & Business Media|isbn=978-94-007-7347-9|pages=9|language=en}}

In Silene, since there is no monoecy, it is suggested that dioecy evolved through gynodioecy.{{Cite journal|last1=Casimiro-Soriguer|first1=Inés|last2=Buide|first2=Maria L.|last3=Narbona|first3=Eduardo|date=2015-01-01|title=Diversity of sexual systems within different lineages of the genus Silene|url=https://doi.org/10.1093/aobpla/plv037|journal=AoB Plants|volume=7|issue=plv037|pages=plv037|doi=10.1093/aobpla/plv037|pmid=25862920|issn=2041-2851|pmc=4433491}}

{{One source section|date=June 2021}}

Very few dioecious fungi have been discovered.{{Cite book|last=Gupta|first=Rajni|url=https://books.google.com/books?id=uPCATfIDZBoC&q=dioecy+in+fungi&pg=PA77|title=A Textbook of Fungi|publisher=APH Publishing|isbn=978-81-7648-737-5|pages=77|language=en}}

Monoecy and dioecy in fungi refer to the donor and recipient roles in mating, where a nucleus is transferred from one haploid hypha to another, and the two nuclei then present in the same cell merge by karyogamy to form a zygote.{{cite journal |author=Esser, K. |year=1971 |title=Breeding systems in fungi and their significance for genetic recombination |journal=Molecular and General Genetics |volume=110 |issue=1 |pages=86–100 |doi=10.1007/bf00276051|pmid=5102399 |s2cid=11353336 }} The definition avoids reference to male and female reproductive structures, which are rare in fungi. An individual of a dioecious fungal species not only requires a partner for mating, but performs only one of the roles in nuclear transfer, as either the donor or the recipient. A monoecious fungal species can perform both roles, but may not be self-compatible.

Dioecy has the demographic disadvantage compared with hermaphroditism that only about half of reproductive adults are able to produce offspring. Dioecious species must therefore have fitness advantages to compensate for this cost through increased survival, growth, or reproduction. Dioecy excludes self-fertilization and promotes allogamy (outcrossing), and thus tends to reduce the expression of recessive deleterious mutations present in a population.{{cite journal |vauthors=Charlesworth D, Willis JH |title=The genetics of inbreeding depression |journal=Nat. Rev. Genet. |volume=10 |issue=11 |pages=783–96 |year=2009 |pmid=19834483 |doi=10.1038/nrg2664 |s2cid=771357 }} In trees, compensation is realized mainly through increased seed production by females. This in turn is facilitated by a lower contribution of reproduction to population growth, which results in no demonstrable net costs of having males in the population compared to being hermaphroditic.{{cite journal |last1=Bruijning |first1=Marjolein |last2=Visser |first2=Marco D. |last3=Muller-Landau |first3=Helene C. |last4=Wright |first4=S. Joseph |last5=Comita |first5=Liza S. |last6=Hubbell |first6=Stephen P. |last7=de Kroon |first7=Hans |last8=Jongejans |first8=Eelke |title=Surviving in a Cosexual World: A Cost-Benefit Analysis of Dioecy in Tropical Trees |journal=The American Naturalist |volume=189 |issue=3 |year=2017 |pages=297–314 |issn=0003-0147 |doi=10.1086/690137|pmid=28221824 |hdl=2066/168955 |s2cid=6839285 |hdl-access=free }} Dioecy may also accelerate or retard lineage diversification in angiosperms. Dioecious lineages are more diversified in certain genera, but less in others. An analysis suggested that dioecy neither consistently places a strong brake on diversification, nor strongly drives it.{{cite journal |last1=Sabath |first1=Niv |last2=Goldberg |first2=Emma E. |last3=Glick |first3=Lior |last4=Einhorn |first4=Moshe |last5=Ashman |first5=Tia-Lynn |last6=Ming |first6=Ray |last7=Otto |first7=Sarah P. |last8=Vamosi |first8=Jana C. |last9=Mayrose |first9=Itay |title=Dioecy does not consistently accelerate or slow lineage diversification across multiple genera of angiosperms |journal=New Phytologist |volume=209 |issue=3 |year=2016 |pages=1290–1300 |doi=10.1111/nph.13696|pmid=26467174 |doi-access=free }}

• Gonochorism
• Hermaphrodite
• Plant reproductive morphology
• Self-incompatibility in plants
• Sexual dimorphism
• Trioecy

{{reflist|refs=

{{cite book |last=Kliman |first=Richard |date=2016 |title=Encyclopedia of Evolutionary Biology |publisher=Academic Press |isbn=978-0-12-800426-5 |url=https://books.google.com/books?id=_r4OCAAAQBAJ |archive-url=https://web.archive.org/web/20210506205920/https://www.google.com/books/edition/Encyclopedia_of_Evolutionary_Biology/_r4OCAAAQBAJ?hl=en&gbpv=0&kptab=overview |archive-date=May 6, 2021}} [https://archive.org/details/encyclopediaofevolutionarybiology Alternative archive URL]

{{cite journal|title=Evolution of Dioecy in Flowering Plants|author=K. S. Bawa |journal=Annual Review of Ecology and Systematics|volume=11|year=1980 |pages=15–39 |doi=10.1146/annurev.es.11.110180.000311|jstor = 2096901}}

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• {{Cite book |last=Beentje |first=Henk |year=2010 |title=The Kew Plant Glossary |publication-place=Richmond, Surrey |publisher=Royal Botanic Gardens, Kew |isbn=978-1-84246-422-9 }}
• {{Cite book |last=Mauseth |first=James D. |title=Botany : An Introduction to Plant Biology |edition=5th |year=2014 |isbn=978-1-4496-6580-7 |publisher=Jones and Bartlett Learning |location=Sudbury, MA}}

Category:Plant sexuality

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Category:Sexual reproduction

Category:Reproductive system

Category:Sexual system