The pollination Is the process through which pollen is transferred to the female reproductive organs of a plant, thus allowing fertilization to take place. Pollen is transmitted through vectors such as insects, wind, water or certain animals.
Like all living organisms, flower plants have one main goal: to pass their genetic information to the next generation. One of the ways in which plants reproduce is by producing seeds that contain the genetic information to generate a new plant.
Plants use flowers as tools to provide seeds, which can only be produced when pollen is transferred between flowers capable of freely crossing each other (ie of the same species).
Pollination process
The transfer of pollen into and among the flowers of the same species leads to fertilization, and the successful production of seeds and fruits.
For this, the flowers must rely on the vectors to move the pollen , Being these the ones in charge to transfer the pollen of plant to plant.
They are called pollinators, and can be distinguished in vectors: abiotic (such as wind or water) and biotic (which includes insects - such as bees and butterflies - birds - such as hummingbirds - as well as mice, Birds and other animals that visit the flowers).
Pollination occurs within the same flower, or between several flowers, whether or not the same plant; Depending on the species of plant and its properties, pollination will or will not end in fertilization.
Generally, pollination is the unintended consequence of an animal's activity on a flower. The pollinator usually eats or collects pollen for its protein and other nutritional characteristics or drinks the nectar from the flower, at which point the pollen grains attach to your body.
When the animal visits another flower for the same reason, pollen may accidentally fall into the stigma of the flower and become successful in its reproduction.
Once on the stigma, pollen can germinate, which means that a pollen tube forms on the sticky surface of the stigma and grows on the plant's egg.
The plants can be:
- Angiosperms , Their gametes are propagated by the wind and by the pollinators of insects and animals attracted by their flowers. T
- Gymnosperms, these non-floral seed plants have uncovered eggs to which pollen is transferred. Their pollination is simple, since the spores of pollen are propagated only by the wind.
Types of pollination
Self-pollination
Self-pollination is the most basic type of pollination since it only involves one flower. This type of pollination occurs when the pollen grains of the anther fall directly on the stigma of the same flower.
Although this type of pollination is simple and rapid, it results in a reduction in genetic diversity because the sperm and eggs of the same flower share the same genetic information.
Cross-pollination
On the other hand, cross-pollination is a more complex type of pollination involving the transfer of pollen from the anther of a flower to the stigma of a different flower.
This type of pollination results in an increase in genetic diversity because different flowers are sharing and blending their genetic information to create unique offspring.
Pollination Strategies
Cross-pollination requires the movement of pollen from one flower to another. There are several strategies that flowering plants use to move pollen from one flower to another, including wind, water, and animal pollinators.
Wind is a key vector for transporting pollen over long distances. Plants that use the wind to transport pollen, often have small, light and soft pollen grains.
These plants are usually found in large populations, as this increases the likelihood that the pollen grain will land on a flower of the same species.
Pollination by animal vectors is also a very important type of pollination. It is estimated that about 80% of all flowering plants and 75% of staple crops require animals to help complete the pollination process.
Some plants, on the other hand, depend on water to transport their pollen to other flowers, although this strategy is less common. This transport of pollen through water may involve rainwater or waterways, such as streams.
In gardening, cross-pollination is often used intentionally to create new varieties, for example, it is common to cross tomato species.
Importance of bumblebees
Some insects, like the bumblebee, are great vectors pollinators. The pollen attached to your body is stored in the hind legs.
Although this pollen can not reach the stigma of the flower, pollination occurs only by the loose pollen that is released from your body. Bumblebees are very efficient vectors, as they visit more flowers than a bee, transporting more pollen, and more easily accessing the stamens and pistils.
Also, unlike bees, bumblebees better withstand the different climatic and geographical circumstances, being able to work even with strong winds, rain or cold, as well as in reduced greenhouses.
Another distinctive feature lies in the wide variety of crops that the bumblebee visits, facilitating cross-pollination, much needed in fruits.
Importance of pollination
Around the world, approximately 1,000 plants grown for food, beverages, fibers, spices and medicines need to be pollinated by animals to produce the products on which we depend.
Food and beverages produced with the help of pollinators range from various fruits and vegetables to grains such as cocoa and coffee.
However, globally, there is worrying evidence that pollinator animals see their habitat at risk, because of chemical misuse, invasion of other animal species, diseases and parasites.
References
- "Pollinators"Forest Service. USDA. United States Department of Agriculture (2017) Washington D.C. Retrieved from: fs.fed.us
- "What is pollination and who are the pollinators?"In: Pollinator Partnership NAPPC California (2015) Retrieved from: pollinator.org
- "What is pollination?"On: Pollinator Paradise Retrieved from: pollinatorparadise.com
- "Pollination & Botanical Research"in: Save the Elephants. Recovered from: elephantsandbees.com
- Proctor, M.; Yeo, P.; Lack, A."The natural history of pollination"in"The natural history of pollination"(UK, 1996) Department of Biological Sciences, University of Exeter, UK.
- Faegri, L. Van Der Pijl"Principles of Pollination Ecology"3rd Ed (UK, 1979). Retrieved from: books.google.com
- Russell, S."Pollination and Fertilization"in: Biology Encyclopedia Forum: Biology Reference. Retrieved from: biologyreference.com
- "Types of pollination"in: Casa de la Miel. Cabildo of Tenerife. Spain Recovered from: casadelamiel.org
- "Angiosperms Vs. Gymnosperms"Diffen.com. Diffen LLC, n.d. Web. 3 May 2017 Retrieved from: diffen.com
- "Cross pollinate"in: Pollen Strategy, Australia. Recovered from: pollenstrategy.com.au