WHAT IS DIRECT POLLINATION? - BIOLOGY - 2025

The pollinated, also known as self - pollination or selfing, is the process by which a fertile flower itself, without involving other factors.

To carry out the pollination process, the participation of pollinating agents is normally necessary, which can be elements of nature, such as water or wind, or they can be living beings, such as bees, beetles, hummingbirds, butterflies, flies, bats and humans, among others.

These elements or organisms are in charge of moving the pollen from one flower to the stigma of another, and initiating fertilization. Now, in the case of direct pollination, the flowers are capable of fertilizing themselves, because the pollen falls directly on the stigma of the same flower.

How does direct pollination occur?

At the time of fertilization, the flowers, which are the reproductive organs of plants, let out pollen grains from the anthers, located at the ends of the stamens.

Pollination is generated when these grains go to the stigma of a flower, located in the pistil; this is the place where fertilization takes place.

For this to happen, both the anthers and the stigmas must mature at the same time, so that they can coincide at the time of greatest reproductive possibility and, finally, they can generate effective fertilization.

In addition to direct pollination, there is also indirect pollination, known as cross pollination or allogamy. This type of pollination is characterized by the fact that pollen moves from one flower to another, so that fertilization is generated between different individuals.

Then, in direct pollination, the pollen of a flower fertilizes this same flower, or also different flowers of the same organism. This last process is known as geitonogamy.

Some examples of self-pollinated species are tomatoes, peas, beans, dates, and some orchids.

Direct pollination can be positive in that it allows plants not to depend on external agents for their reproduction, but it can also be negative in that, through self-pollination, a single variety of plant is produced.

Advantage

Pollinator independence

The main advantage is that plants that practice direct pollination have a better chance of surviving if there are no pollinators in their area.

These continue to reproduce without depending on other organisms or elements of nature that activate the fertilization process.

Fast play

Self-pollination promotes rapid reproduction, since the participation of external agents is not contemplated. That is, you should not wait for a pollinator to take the pollen and then transfer it to another flower.

Since the process takes place in the same plant, it is much faster: waiting times related to transfers should not be taken into account.

Lower danger of extinction

There are areas where pollinating agents are not easily accessible, or have become extinct for different reasons.

In these specific cases, self-pollinating plants have a greater chance of survival, since they do not depend on external pollinators.

Disadvantages

Little genetic diversity

Since the transmission of genes is always between the same plant, the genetic information that is transferred ends up being not very diverse, which implies that the result will be a very uniform species, with little variability.

This constitutes a disadvantage because a species with little possibility of adaptation to environmental changes can be generated.

Small flowers

As a consequence of the high consanguineous degree generated by direct pollination, the flowers that are generated from this fertilization process tend to be of lower quality.

They are smaller, in some cases opaque, without nectar and without fragrance, since it is not necessary to attract external pollinators. On the other hand, the flowers generated from indirect or cross pollination are characterized by being more beautiful, firm and with greater resistance.

Eventually, the flowers generated through direct pollination generate little amount of pollen, which can mean the extinction of the species in question.

Inhibition of the self-pollinating gene

Recent research has focused on discovering ways to disable the gene that allows direct pollination in plants.

The need for this study is generated, among other reasons, by the importance for many farmers to be able to have the possibility of improving crops and producing stronger and higher quality species, through hybridization (mixture of different organisms to generate a new one).

For this, they have focused on carefully studying those plants that do not generate the process of self-pollination, because their very structure recognizes the pollen itself and rejects it.

There are organisms that can even activate or deactivate the self-pollination process depending on what is most convenient for the species.

For example, a plant may have a predisposition to carry out cross pollination but, if a certain period elapses and this plant is not pollinated by external factors, it is capable of generating direct pollination or self-pollination.

This is considered to be the most desirable characteristic in plant organisms, since they could have even greater resistance to external factors.

It is a self-sufficient species and, at the same time, with the ability to carry out the indirect pollination process, which guarantees efficient reproduction, with the possibility of originating robust organisms with a better and more complex genetic load.

The research is being carried out by Botany Professor June Nasrallah, and a team of researchers from Cornell University, in New York, United States.

The intention of this research is to understand the functioning of these plants that reject their own pollen, and thus be able to study the ways of transferring it to other plants that have the predisposition to carry out direct pollination.

References

1. "Pollination" in ABC Color. Retrieved on August 22, 2017 from ABC Color: abc.com.py.
2. "What is pollination?" in Green Generation. Retrieved on August 22, 2017 from Generación Verde: generacionverde.com.
3. "New finding about genes that activate or deactivate the plant's ability to self-pollinate" in Just Science. Retrieved on August 22, 2017 from Only Science: solociencia.com.
4. Gardapee, P. "Self-pollination vs. cross-pollination" in eHow in Spanish. Retrieved on August 22, 2017 from eHow in Spanish: ehowenespanol.com.
5. "Plants that do not self-pollinate tend to hybridize with other species" (January 17, 2013) in the Higher Council for Scientific Research. Retrieved on August 22, 2017 from the Higher Council for Scientific Research: csic.es.
6. Holmgren, L. "Types of flowers that self-pollinate" in eHow in Spanish. Retrieved on August 22, 2017 from eHow in Spanish: ehowenespanol.com.