Everything about Parthenocarpy totally explained
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's 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.
Utah juniper has a similar defense against bird feeding. 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's a
triploid -meaning it's the result of a diploid and a tetraploid parent and therefore can't produce seeds. Plants that don't 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 don't 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're 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.
Some parthenocarpic cultivars are of ancient origin. The oldest known cultivated plant is a parthenocarpic fig first grown at least 11,200 years ago.
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.(External Link
) 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.
Further Information
Get more info on 'Parthenocarpy'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://parthenocarpy.totallyexplained.com">Parthenocarpy Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |
