Faculty of science, School of Sciences, Natabua campus Lautoka BIO706: Embryology Lecture 29: Parthenocarpy

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. Ex: Banana, Tomato, Lemon, Watermelon, Grapes, Cucumber etc.

Stenospermocarpy may also produce apparently seedless fruit, but the seeds are actually aborted while still small. Parthenocarpy (or stenospermocarpy) occasionally occurs as a mutation in nature; if it affects every flower, the plant can no longer sexually reproduce but might be able to propagate by vegetative means.

The process where fruits are formed in a flower which hasn't gone through the process of fertilization is called 'Parthenocarpy'. This formation of the fruit can happen naturally or artificially. Artificially, farmers spray growth hormone, called Auxins, that enables the growth of the fruit. A fruit that is developed in this manner is called a parthenocarpic fruit.

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 other stimulation is required for parthenocarpy. This is termed stimulative parthenocarpy. Plants that do not require pollination or other stimulation to produce parthenocarpic fruit have vegetative parthenocarpy. Cucumber is an example of vegetative parthenocarpy, seedless watermelon is an example of stenospermocarpy.

Plants moved from one area of the world to an other 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 seen as a 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.

Parthenocarpic Brinjal & Squash

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 Some cucumbers produce seedless fruit if pollinators are excluded. Strange as it seems, seedless watermelon plants are grown from seeds. The seeds are produced by crossing a diploid parent(2n) with a tetraploid parent to produce triploid seeds (3n)

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 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 due to lack of pollination.

Parthenocarpic Cucumber

Seedless Watermelon

Thank You Questions are welcome