Editing Parthenocarpy

{{Short description|Production of seedless fruit without fertilisation}}
[[File:Watermelon seedless.jpg|right|thumb|Seedless watermelon]]
In [[botany]] and [[horticulture]], '''parthenocarpy''' is the natural or artificially induced [[Horticulture industry|production]] of [[fruit]] without [[fertilisation]] of [[ovule]]s, which makes the fruit seedless. The phenomenon has been observed since ancient times<ref>{{Cite journal |last=Gustafson |first=Felix G. |date=1942-11-01 |title=Parthenocarpy: Natural and artificial |url=https://doi.org/10.1007/BF02881046 |journal=The Botanical Review |language=en |volume=8 |issue=9 |pages=599–654 |doi=10.1007/BF02881046 |bibcode=1942BotRv...8..599G |s2cid=26990263 |issn=1874-9372|url-access=subscription }}</ref> but was first scientifically described by German botanist [[Fritz Noll]] in 1902.<ref>{{Cite journal |last=Noll |first=F. |date=1902 |title=Fruchtbildung ohne vorausgegangene Bestaubung (Parthenokarpie) bei der Gurke |journal=Gesellschaft für Natur- und Heilkunde zu Bonn |volume=1 |pages=149–162}}</ref>

[[Stenospermocarpy]] may also produce apparently [[seedless fruit]], but the seeds are actually aborted while they are still small. Parthenocarpy (or stenospermocarpy) occasionally occurs as a mutation in nature; if it affects every flower, the plant can no longer [[sexual reproduction of plants|sexually reproduce]]{{cn|date=May 2020}} but might be able to propagate by [[apomixis]] or by [[vegetative reproduction|vegetative]] means. Examples of this include many citrus varieties that undergo [[nucellar embryony]] for reproduction, instead of solely sexual reproduction, and can yield seedless fruits.

== Ecological importance ==
Parthenocarpy of some fruits on a plant may be of value. Up to 20% of the fruits of wild [[parsnip]] are parthenocarpic. The seedless wild parsnip fruit are preferred by certain herbivores and so serve as a "decoy defense" against [[seed predation]].<ref>{{cite journal |vauthors=Zangerl AR, Nitao JK, Berenbaum MR |title=Parthenocarpic fruits in wild parsnip: decoy defence against a specialist herbivore |journal=Evolutionary Ecology |volume=5 |pages=136–45 |year=1991 |doi=10.1007/BF02270830 |issue=2 |bibcode=1991EvEco...5..136Z |s2cid=44584261 }}</ref> [[Juniperus osteosperma|Utah juniper]] has a similar defense against bird feeding.<ref>{{cite journal |vauthors=Fuentes M, Schupp EW |title=Empty seeds reduce seed predation by birds in ''Juniperus osteosperma'' |journal=Evolutionary Ecology |volume=12 |pages=823–7 |year=1998 |doi=10.1023/A:1006594532392 |issue=7|bibcode=1998EvEco..12..823F |s2cid=19570153 }}</ref> The ability to produce seedless fruit when [[pollination]] is unsuccessful may be an advantage to a plant because it provides food for the plant's seed dispersers. Without a fruit crop, the seed dispersing animals may starve or migrate.

In some plants, pollination or another stimulation is required for parthenocarpy, termed '''stimulative parthenocarpy'''. Plants that do not require pollination or other stimulation to produce parthenocarpic fruit have '''vegetative parthenocarpy'''. Seedless [[cucumber]]s are an example of vegetative parthenocarpy, seedless [[watermelon]] is an example of stenospermocarpy as they are immature seeds (aborted ones).

Plants that moved from one area of the world to another may not always be accompanied by their pollinating partner, and the lack of [[pollinator]]s has spurred human cultivation of parthenocarpic varieties.

== Commercial importance ==
Seedlessness is seen as a desirable trait in edible fruit with hard seeds such as [[banana]], [[pineapple]], [[orange (fruit)|orange]] and [[grapefruit]]. Parthenocarpy is also desirable in fruit crops that may be difficult to pollinate or fertilize, such as [[Ficus carica|fig]], [[tomato]] and summer [[Squash (fruit)|squash]]. In [[Dioecy|dioecious]] species, such as [[persimmon]], parthenocarpy increases fruit production because staminate trees do not need to be planted to provide pollen. Parthenocarpy is undesirable in nut crops, such as [[pistachio]], for which the seed is the edible part. Horticulturists have selected and propagated parthenocarpic [[cultivar]]s of many plants, including [[banana]], [[Common fig|fig]], cactus pear (''[[Opuntia]]''), [[breadfruit]] and [[eggplant]]. Some plants, such as pineapple, produce seedless fruits when a single cultivar is grown because they are self-infertile. Some [[cucumber]]s produce seedless fruit if [[pollinator]]s are excluded. Seedless watermelon plants are actually grown from seeds. The seeds are produced by crossing a diploid parent with a tetraploid parent to produce [[triploid]] seeds. It has been suggested that parthenocarpy could explain the difference in the yields in [[Natural product|active compounds]] of the genus ''[[Cannabis]]''.<ref>{{Cite journal |last=Riboulet-Zemouli |first=Kenzi |date=2020 |title='Cannabis' ontologies I: Conceptual issues with Cannabis and cannabinoids terminology |journal=Drug Science, Policy and Law |language=en |volume=6 |pages=205032452094579 |doi=10.1177/2050324520945797 |s2cid=234435350 |issn=2050-3245|doi-access=free }}</ref><ref>{{Cite journal |last1=Trancoso |first1=Ingrid |last2=de Souza |first2=Guilherme A. R. |last3=dos Santos |first3=Paulo Ricardo |last4=dos Santos |first4=Késia Dias |last5=de Miranda |first5=Rosana Maria dos Santos Nani |last6=da Silva |first6=Amanda Lúcia Pereira Machado |last7=Santos |first7=Dennys Zsolt |last8=García-Tejero |first8=Ivan F. |last9=Campostrini |first9=Eliemar |date=2022 |title=Cannabis sativa L.: Crop Management and Abiotic Factors That Affect Phytocannabinoid Production |journal=Agronomy |language=en |volume=12 |issue=7 |pages=1492 |doi=10.3390/agronomy12071492 |doi-access=free |bibcode=2022Agron..12.1492T |issn=2073-4395}}</ref> 

Some parthenocarpic cultivars are of ancient origin. The oldest known cultivated plant is a parthenocarpic fig that was first grown at least 11,200 years ago in [[Jordan Valley]].<ref>{{cite journal |vauthors=Kislev ME, Hartmann A, Bar-Yosef O |date=June 2006 |title=Early domesticated fig in the Jordan Valley |journal=Science |volume=312 |issue=5778 |pages=1372–4 |bibcode=2006Sci...312.1372K |doi=10.1126/science.1125910 |pmid=16741119 |s2cid=42150441}}</ref> 

In some climates, normally-seeded [[pear]] cultivars produce mainly seedless fruit for lack of pollination.<ref>[https://web.archive.org/web/20071121043502/http://extension.oregonstate.edu/catalog/html/ec/ec986/ R.L. Stebbins, W.M. Mellenthin, and P.B. Lombard (1981) ''Pollination & Commercial Varieties of Pears in Oregon'' Oregon State University Extension Service.]</ref>

When sprayed on flowers, any of the [[plant hormone]]s [[gibberellin]], [[auxin]] and [[cytokinin]] could stimulate the development of parthenocarpic fruit. That is termed '''artificial parthenocarpy'''. Plant hormones are seldom used commercially to produce parthenocarpic fruit. Home gardeners sometimes spray their tomatoes with an auxin to assure fruit production.<ref>{{cite journal|title=Seedless Fruit Production by Hormonal Regulation of Fruit Set
|journal=Nutrients
|volume=1
|issue=2
|pages=168–177
|first=Tiziana|last=Pandolfini|publisher=[[University of Verona]]|date=23 November 2009|pmc=3257607
|pmid=22253976
|doi=10.3390/nu1020168
|doi-access=free
}}</ref>

Some parthenocarpic cultivars have been developed as [[genetically modified organism]]s.<ref>{{cite journal |vauthors=Pandolfini T, Rotino GL, Camerini S, Defez R, Spena A |title=Optimisation of transgene action at the post-transcriptional level: high quality parthenocarpic fruits in industrial tomatoes |journal=BMC Biotechnol. |volume=2 |page=1 |year=2002 |pmid=11818033 |pmc=65046 |doi=10.1186/1472-6750-2-1 |doi-access=free }}</ref><ref>{{Cite journal | last1 = Acciarri | first1 = N. | last2 = Restaino | first2 = F. | last3 = Vitelli | first3 = G. | last4 = Perrone | first4 = D. | last5 = Zottini | first5 = M. | last6 = Pandolfini | first6 = T. | last7 = Spena | first7 = A. | last8 = Rotino | first8 = G. | title = Genetically modified parthenocarpic eggplants: Improved fruit productivity under both greenhouse and open field cultivation | journal = BMC Biotechnology | volume = 2 | pages = 4 | year = 2002 | doi = 10.1186/1472-6750-2-4 | pmid =  11934354| pmc =101493 | doi-access = free }}</ref>

== Misconceptions ==
* Most commercial seedless grape cultivars, such as 'Thompson Seedless', are seedless not because of parthenocarpy but because of [[stenospermocarpy]].<ref>Mullins, M., Bouquet, A., Edward, L. (1992). {{cite book|url=https://books.google.com/books?id=wnNvmRjfxgQC&q=viticulture+stenospermocarpy&pg=PA75|title=''Biology of the grapevine''|isbn=9780521305075|last1=Mullins|first1=Michael G.|last2=Bouquet|first2=Alain|last3=Williams|first3=Larry E.|date=1992-07-16|publisher=Cambridge University Press }}. Cambridge University Press, p. 75.</ref>
* Parthenocarpy is sometimes claimed to be the equivalent of [[parthenogenesis]] in animals.<ref>{{cite web|url=http://www.bartleby.com/65/pa/partheno.html|archiveurl=https://web.archive.org/web/20080628154204/http://www.bartleby.com/65/pa/partheno.html|title=parthenogenesis. The Columbia Encyclopedia, Sixth Edition. 2001-07|archivedate=28 June 2008|work=bartleby.com}}</ref> That is incorrect because parthenogenesis is a method of asexual reproduction, with embryo formation without fertilization, and parthenocarpy involves fruit formation, without seed formation. The plant equivalent of parthenogenesis is [[apomixis]].

== References ==
{{reflist|30em}}

== External links ==
* {{cite journal |author=Weiss, J., Nerd, A. and Mizrahi, Y |title=Vegetative parthenocarpy in the cactus pear ''Opuntia ficus-indica'' (L.) Mill |journal=Annals of Botany |volume=72 |issue=6 |pages=521–6 |year=1993 |doi=10.1006/anbo.1993.1140 |bibcode=1993AnBot..72..521W }}

[[Category:Plant morphology]]
[[Category:Plant reproduction]]