Pollination is the initial reproductive stage that plants do to reproduce. Usually, this requires two plants. However, a technique by which a plant may pollinate itself is known as self-pollination. This article will discuss what it is, how it varies from cross-pollination, and if this method has more advantages than downsides.
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What is Self-Pollination and other Types of Pollination?
Pollination is required for male anthers to reach the stigma situated on the pistil and germinate. The pollen tube grows from this, connecting the male and female gametes to fertilize each other and produce the diploid zygote.
The pistil is sticky to make self-pollination simple, allowing pollen to be readily captured as it approaches the stamens. This is most commonly seen during cleistogamy, a process in which pollination begins before the flower opens, taking advantage of the proximity of the pistils and stamens. When the flower is open, any movement permits pollen grains to reach the female stigma, resulting in self-pollination. In extreme instances, certain plants may wait for pollination and then close and self-pollinate if it does not occur.
Direct pollination, which includes self-pollination, is the most unusual way for pollination to occur. In this situation, the plants have the stamens to pollinate the stigma of the same flower without the need for an external pollinator.
These species self-pollinate, which means that the male and female gametes of the same plant combine. Because they require both plant reproductive mechanisms, any plants that can self-pollinate must be hermaphrodites.
Types of Pollination
Pollination can also be characterized as natural or artificial. We shall take a closer look at them in the sections that follow:
Natural pollination can be entomogenous (involved by insects such as bees) or zoophilic (affected by animals such as birds when pollen adheres to feathers or animal fur). It can also be transported by abiotic mechanisms, such as being anemophilous, in which the wind aids in pollination, or hydrophilous, in which water conveyance is used.
Artificial pollination occurs when he intervenes in the fertilization process. This approach is utilized when better control over the progeny is required to have certain features or when there is a lack of pollinators by isolation, particularly for agricultural pollination. It is possible to transmit pollen with a stick or brush.
Difference between Self-Pollination and Cross-Pollination
Self-pollination and cross-pollination are two distinct methods of pollination. As a result, we shall now discuss the distinctions between self-pollination and cross-pollination.
Self-pollination does not require any external materials to pollinate it, nor does it require pollen from other plants of the same species. Self-pollinating plants’ blooms may be tiny and not as vividly colored since they have not needed to evolve these methods. Self-pollinating plants are the rarest. Peas, Santa Rosa plum (Prunus domestica), tomatoes, soybeans, and specific orchids, such as Ophrys apifera, are examples of self-pollinating plants.
The most prevalent type of plant is one that has been cross-pollinated. Cross-pollination requires pollen from other plants. Natural modes of movement such as wind, water, or insects are necessary for this cross-pollination, and the blooms have brilliant colors that arthropod eyesight reacts to.
Advantages and Disadvantages of Self-Pollination
Because self-pollination is a relatively unusual reproductive method, it has advantages and downsides.
Advantages of Self-Pollination
Some of the advantages involved in the whole process of self-pollination are:
They do not require external causes to complete their reproduction, which means they do not rely on other plants of their species to pollinate, allowing them to thrive wherever they are inserted and often becoming invasive plants, pests, or weeds.
Zero pollen waste: pollen is not wasted to the wind, water, or animals, allowing for more effective creation of these reproductive cells. This benefit of autogamy is significant for tiny flowers, which cannot generate vast volumes of pollen and must consume as much as possible.
Generation of descendants: with purer ancestors and more homogeneous DNA.
Adaptation to specific ecosystems: Each successive generation of plants reproduces plants equally well suited to the particular environment they currently occupy.
Disadvantages of Self-Pollination
Some of the disadvantages of the self-pollination process are the following:
Genetic impairment caused by a lack of recombination: the goal of self-fertilization is to increase the number of homozygotes for recessive genes to be expressed, but because it is an inbreeding type of reproduction, it causes a reduction in genetic recombination, resulting in the accumulation of harmful recessive genes.
Reduced adaptive plasticity: a lack of genetic interchange exposes them to pests, illnesses, or environmental changes for which they have not established adaption methods.
Fertility impairment is pretty prevalent in all creatures that reproduce in endogamic ways.
In plants, on the other hand, homozygosis frequently results in outstanding adaptations to specific habitats, reproducing equally well-suited plants in each subsequent generation.
