Parthenocarpy


Parthenocarpy

In botany and horticulture, parthenocarpy (literally meaning virgin fruit) is the natural or artificially induced production of fruit without fertilization of ovules. The fruit is therefore seedless. Parthenocarpy occasionally occurs as a mutation in nature, but it is usually considered a defect, as the plant can no longer sexually reproduce, but may propagate by asexual means.

However, 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 so serve as a "decoy defense" against seed predation. [Zangerl, A.R., J.K. Nitao, and M.R. Berenbaum. 1991. Parthenocarpic fruits in wild parsnip: decoy defence against a specialist herbivore. "Evolutionary Ecology" 5:136-145.] Utah juniper has a similar defense against bird feeding. [Fuentes, M. and Schupp, E.W. 1998. Empty seeds reduce seed predation by birds in "Juniperus osteosperma." "Evolutionary Ecology" 12: 823-827. [http://www.udc.es/dep/bave/marcelino/FuentesSchupp1998.pdf] ] Being able 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, such as seedless watermelon, pollination or other stimulation is required for parthenocarpy. This is termed stimulative parthenocarpy. Banana exhibits stimulative parthenocarpy because it is a triploid -meaning it is the result of a diploid and a tetraploid parent and therefore cannot produce seeds. Plants that do not require pollination or other stimulation to produce parthenocarpic fruit have vegetative parthenocarpy. Cucumber is an example of vegetative parthenocarpy.

Plants moved from one area of the world to another may not always be accompanied by their pollinating partner and the lack of pollinators has spurred human cultivation of parthenocarpic varieties. Some parthenocarpic varieties have been developed as genetically modified organisms.

Commercial importance

Seedlessness is a very desirable trait in edible fruit with hard seeds such as pineapple, banana, orange and grapefruit. Parthenocarpy is also desirable in fruit crops that may be difficult to pollinate or fertilize, such as tomato and summer squash. In 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, where the seed is the edible part. Horticulturists have selected and propagated parthenocarpic cultivars of many plants, including 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 cucumbers produce seedless fruit if pollinators are excluded. Strange as it seems, seedless watermelon is propagated by seed. The seeds are produced by crossing a diploid parent with a tetraploid parent to produce triploid seeds.

When sprayed on flowers, any of the plant hormones, gibberellin, auxin and cytokinin, can often stimulate the development of parthenocarpic fruit. This 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.

Some parthenocarpic cultivars have been developed as genetically modified organisms. [Pandolfini, T., Rotino, G.L., Camerini, S., Defez, R. and Spena, A. 2002. Optimisation of transgene action at the post-transcriptional level: High quality parthenocarpic fruits in industrial tomatoes. "BMC Biotechnol." 2: 1. [http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=65046] ]

Some parthenocarpic cultivars are of ancient origin. The oldest known cultivated plant is a parthenocarpic fig first grown at least 11,200 years ago. [Kislev, M.E., Hartmann, A. and Bar-Yosef, O. 2006. Early domesticated fig in the Jordan Valley. "Science" 312: 1372-1374. [http://www.sciencemag.org/cgi/content/abstract/sci;312/5778/1372] ]

In some climates, normally seeded pear cultivars will produce mainly seedless fruit.

Misconceptions

*Most commercial seedless grape cultivars, such as 'Thompson Seedless' are not seedless because of parthenocarpy, but because of stenospermocarpy.
*Parthenocarpy is sometimes claimed to be the equivalent of parthenogenesis in animals. [http://www.bartleby.com/65/pa/partheno.html] That is incorrect because parthenogenesis is a method of asexual reproduction, and parthenocarpy is not, except in rare cases such as pineapple. The plant equivalent of parthenogenesis is apomixis.

References

ee also

* Seedless fruit
* Stenospermocarpy

External links

* [http://aob.oxfordjournals.org/cgi/reprint/72/6/521 Weiss, J., Nerd, A. and Mizrahi, Y. 1993. Vegetative parthenocarpy in the cactus pear "Opuntia ficus-indica" (L.) Mill. "Annals of Botany" 72: 521-526.]


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • parthenocarpy — parthenocarpy. См. партенокарпия. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • parthenocarpy — [pär′thə nō kär΄pē] n. [Ger parthenokarpie < Gr parthenos, a virgin + karpos, fruit: see HARVEST] the development of a ripe fruit without fertilization of the ovules, as in the banana and pineapple parthenocarpic adj. parthenocarpically adv …   English World dictionary

  • parthenocarpy — noun Etymology: International Scientific Vocabulary, from Greek parthenos virgin + karpos fruit more at harvest Date: 1911 the production of fruits without fertilization < bananas set fruit by parthenocarpy and without pollination > •… …   New Collegiate Dictionary

  • parthenocarpy — parthenocarpic, adj. /pahr theuh noh kahr pee/, n. Bot. the production of fruit without fertilization of an egg in the ovary. [1910 15; PARTHENO + carpy; see CARP, Y3] * * * ▪ botany       development of fruit without fertilization. The fruit… …   Universalium

  • parthenocarpy — partenokarpija statusas T sritis ekologija ir aplinkotyra apibrėžtis Augalų besėklių vaisių susidarymas be apvaisinimo. Būdinga daugeliui kultūrinių augalų (pvz., kai kuriems vynmedžiams, juodmedžiams, kriaušėms, pomidorams). atitikmenys: angl.… …   Ekologijos terminų aiškinamasis žodynas

  • parthenocarpy — partenokarpija statusas T sritis augalininkystė apibrėžtis Augalų vaisių formavimasis be apvaisinimo.Tokie vaisiai neturi sėklų arba sėklose nebūna gemalų. atitikmenys: angl. parthenocarpy rus. партенокарпия …   Žemės ūkio augalų selekcijos ir sėklininkystės terminų žodynas

  • parthenocarpy — Fruit formation without fertilization. Occurs spontaneously in some plants, eg. banana, and in other plants can be induced by application of auxin. Results in seedless fruits …   Dictionary of molecular biology

  • parthenocarpy — noun production of (seedless) fruit without fertilization of ovules. See Also: parthenocarpic …   Wiktionary

  • parthenocarpy — par·the·no·car·py …   English syllables

  • parthenocarpy — /ˈpaθənoʊkapi/ (say pahthuhnohkahpee) noun Botany the production of fruits without fertilisation, either naturally, as is often the case with wild parsnips, or with human intervention, as in the breeding of seedless grapes. {partheno + carp + y1} …   Australian English dictionary


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.