Plants can reproduce and make new species that may or may not have the same genes as them. Plant reproduction process either involves sexual reproduction or asexual reproduction, and both methods provide different genetic products.
Sexual plant reproduction is where the genetic material (DNA) of male and female organs in plants combine to make a new offspring. The offspring of sexual reproduction is called a seed.
Asexual reproduction refers to plants creating offspring using different parts of their bodies. This means the plant will be genetically identical to the parent plant.
Plant reproduction isn’t that different from its human reproduction. Plants use their reproductive organs, like the stamen and the pistil, to transfer male gametes to the female receptive organ.
What Is Plant Reproduction?
Plant reproduction is the process by which plants produce new offspring. This process can involve sexual reproduction or asexual reproduction.
According to Pereira from University of Milan and Coimbra from University of Porto, there’s still much we don’t know about plant reproduction.
As we’ve already established, plants can reproduce sexually and asexually. Let’s see how they differ from each other.
Sexual Reproduction
Sexual reproduction is where the genetic material (DNA) of male and female organs in plants combine to make a new offspring. It’s what most plant owners imagine when they think of plant reproduction.
Phytologists call this process fertilization, and the offspring of sexual reproduction is called a seed. Here’s the thing: since these seeds are the result of combining the cells of two plants, their DNA structure usually differs from both parents.
That genetic evolution gives the offspring an advantage, as it allows them to adapt to environmental changes.
Asexual Reproduction
Asexual reproduction refers to plants creating offspring using different parts of their bodies. Yes, unlike humans, plants can reproduce without merging male and female DNA.
That means the product will be genetically identical to the parent. That’s why most phytologists define asexual reproduction as plants making clones of themselves.
What Is the Anatomy of Plant Reproduction?
The previous sections included words like “stamen and “pistil.” You probably don’t know what they mean.
These are parts of flowering plants that contribute to the reproduction process. The parts of the plant reproduction include:
Sepals
These are green, leafy structures at the outermost part of the flower, protecting unopened flower buds. They usually differ in shape and size depending on the type of flower.
Petals
They’re modified leaves that exist inside sepals and surround the reproductive system of the flowers. They usually have bright, saturated colors, which help attract pollinators.
Pistil
That’s the female reproductive system. It sits in the center of the flower and contains the stigma, style, and ovary.
Stigma
It’s the sticky knob that sits at the top of the pistil structure. It hosts and rehydrates the pollen, prompting the fertilization process.
Style
The style is a long, green, tube-like structure that supports the stigma. It’s the channel that allows the pollen to travel, delivering the sperm to the ovary.
Ovary
The ovary is the enlarged structure that sits at the base of the pistil, where the fertilization process takes place. It hosts the ovules and nourishes the tissues surrounding them.
Ovules
The ovules, aka “the megasporangium,” is a plant structure that lies within the ovary of the flower. During fertilization, the wall of the ovules thickens, prompting their development into seeds. These seeds eventually grow into adult plants.
Stamen
That’s the male reproductive organ in flowering plants. They usually sit at the center of the flower and consist of two parts: A filament and an anther. A few small structures called nectaries live at the base of the stamens to provide food for pollinators.
Anther
It’s a structure that sits at the top of the stamen, producing pollen grains through the process of meiosis. Depending on their structure and shape, anthers can be categorized into bilobed, linear, rounded, reniform, or sagittate.
Filament
It’s a thin, tube-like structure that sits within the stamen and carries nutrients to the anther to help develop pollen grains.
Pollen
It’s a fine powder that flowering plants produce for the purpose of reproduction.
How Do Plants Reproduce?
At this point, you’ve probably formed a general idea about the differences between sexual and asexual reproduction. Ultimately, the choice between both methods depends on the environment.
According to Yang and Kim from Seoul National University, different types of plants lean towards sexual reproduction if they’re sitting in a well-illuminated area. Other types prefer asexual reproduction if they’re sitting in rich, well-watered soil.
That’s barely scratched the surface. Tackling the complexities and nuances of both methods might give you a more accurate idea.
Sexual Reproduction
As we’ve already established, sexual reproduction requires a combination of male and female genetic materials. How does this happen? Let’s find out!
- Pollination
Pollination is the first step in the sexual reproduction process. As the name suggests, it’s when the pollen grains in the anther travel to the stigma.
The process isn’t always the same in every plant. You see, there are two types of pollination:
Self-Pollination
Self-pollination is where the pollen travels from the anther to the stigma of the same flower (Yes, some flowers have male and female organs). That’s not the same as asexual reproduction.
Yes, the process occurs in one flower. It still requires the merging of male and female DNA, though. What does “of the same flower” mean?
Well, self-pollination comes in different forms. What we just covered is called “Autogamy.”
Geitonogamy is another type of self-pollination where pollen grains travel from the anther of a flower to the stigma of another flower of the same plant.
Cross-Pollination
Cross-pollination, aka “Xenogamy,” is where the pollen travels from the anther of a flower to the stigma of another flower in a different plant of the same species.
Several factors can prompt the transfer of pollen in cross-pollination. Live organisms, like insects, birds, butterflies, and vertebrates, are the main contributors. Wind and water can also transfer it.
- Germination
When a pollen grain lands on the stigma of a flower, a tube extends out of it along the cells of the style. It creates a path that connects the sperm inside it to the female gametes in the ovules.
- Fertilization
Fertilization occurs when the male and female gametes merge in the ovules, forming the zygote (egg cell).
The zygote then continues to divide and forms the embryo. Over time, the ovule develops a hard coat and turns into a seed, while the ovary ripens and changes into a fruit.
The fertilization process isn’t universal. It differs from one plant to another, depending on how the pollen tube connects with the ovules.
Porogamy
Porogamy is most common in flowering plants. In this type of fertilization, the pollen tube connects with the ovules through the micropyle.
Chalazogamy
Chalazogamy is common with Casuarina plants. In this scenario, the pollen tube enters the ovule through the chalaza. That’s a fused nucleus that sits at the base of the ovule opposite the micropyle.
Mesogamy
That type of fertilization usually occurs with gourd plants, like ridge gourds and bitter gourds. With mesogamy fertilization, the pollen tube connects with the ovules through its integuments.
It’s worth noting that the pollen tube carries two male gametes, not one. Whichever type of fertilization occurs, one gamete usually fuses with the female gamete, and the other merges with two polar nuclei to form an endosperm.
Asexual Reproduction
We covered the premise of asexual reproduction. We never explained how plants can make clones of themselves, though.
It’s not like they break into a lab, cut a piece of their bodies, and use technology to turn it into a grown clone.
Here’s the thing: There’s more than one way for a plant to reproduce asexually. Let’s see a few examples.
Budding
Budding is where a plant grows out of a protruding part of another plant called the bud.
Vegetative Propagation
Vegetative propagation is a reproduction method where plants grow from the stems, leaves, or roots of other plants. Let’s see how each part factors into the process.
Stem
You can follow the asexual reproduction process in the stem by watching strawberry plants. It usually goes like this:
- The branches develop runner shoots, small stems that branch away from the main one.
- The stems grow along the ground until they reach their peak.
- The stems produce new plants, aka “daughter plants” that are genetically identical to the parent.
Leaves
Although the reproduction process seems complex to most people, this one is quite straightforward.
- Plants grow small leaflets or plantlets at the edge of their primary leaves.
- These leaflets fall and inhabit the same soil as the original plant.
- The leaflets grow into adult plants (if the ideal environment is provided).
Roots
Asexual reproduction in roots is associated with plants that have modified roots. These roots have lateral buds inside them.
The lateral buds can form new shoots, which grow into adult plants over time.
Spore Formation
Spores are reproductive cells capable of growing into new plants without merging with other gametes. Plants usually store them in sacs called sporangia.
Eventually, that sac breaks and the spores disperse, falling on the ground and growing into new adult plants.
Fragmentation
Fragmentation is derived from the word “fragment.” Here’s how it works:
- A small piece, or a fragment, of the plant breaks and falls off.
- That piece receives the same nutrients, water, and fertilizer as the original plant.
- It eventually develops an extensive root system.
Artificial Reproduction
Asexual reproduction isn’t always a natural process. You can recreate it yourself with a few simple steps.
Plant Cutting
Did you think fragmentation was a convenient form of reproduction? It’s a shame you have to wait for these small parts to break off on their own.
Well, you can always give them a small push. This form of reproduction, as the name suggests, requires you to cut a small part of the plant and use it to grow another one. Here’s how it works:
- Cut the node of the plant.
- Dip it end in rooting powder to stimulate root formation.
- Plant it in proper soil.
- Water it regularly and meet all its nutritional needs.
Layering
Think of layering as a less extreme version of plant cutting. You don’t have to go as far as cutting a part of the plant. Then, what do you do?
- Grab a branch of an established plant and bury it in the soil.
- Keeping its tip above the ground so the buried part will function as the root, while the tip will be the shoot system.
- Provide the same nutrients to the new plant as you do to the original one.
Grafting
Say you have two orange trees; one only produces a few delicious oranges, while the other provides many poor-tasting oranges.
Grafting is where you combine the two so they can grow as one organism with the desirable features of both plants. It’s a bit more complex and dangerous than the previous methods, so you want to be careful.
- Cut out a section of the plant with the poor-tasting fruit where it’ll receive the other plant.
- Cut a small part of the one with the delicious fruit and place it in the stock.
- Align the tissues of both plants properly
- Secure their connection with tape or wire.
The most prominent example of grafting is Sam Van Aken’s “Tree of 40 Fruit.” As the name suggests, Sam grafted forty stone fruit trees into one large root system.
It’s also proof of the effectiveness of that reproduction method. Many believe that merging parts of different flowers leads to chaotic results.
Well, one look at Aken’s coherent tree proves that the grafted plants can act as one entity.
Micropropagation
That’s the most scientific method on this list, as it requires you to use chemical tools and solutions that you may not be familiar with.
- Remove a small piece of tissue from the parent plant.
- Put it in a sterile growth medium.
- Leave it until it turns into a small chunk of cells called callus.
- Treat this callus with different concentrations of growth regulators.
- Plant the resulting seeds in the soil and provide water and nutrients.
As you can see, most people can’t use this method. It’s usually exclusive to rare species that can’t grow or reproduce under natural conditions.
What Is Needed for the Plant Production Process?
According to a published article in the Journal of Biological Education by Peter Lampert, Bernhard Müllner, Peter Pany, Martin Scheuch and Michael Kiehn plant reproduction, reproduction won’t occur unless all the elements that contribute to it are there.
The plant production process requires photosynthesis to occur which involves light, water and carbon dioxide. Other factors include temperature, nutrition, pollination, and flowering.
What Is the Male Plant Reproduction Organ?
Without the male reproductive organ, plants can’t reproduce sexually. It’d be like a woman trying to get pregnant without a man.
The male reproductive organ is called the stamen. It’s the overarching structure that consists of the anther and the filament.
The anther is responsible for producing the pollen grains that carry the male gametes, while the filament helps nourish them.
What Is the Female Plant Reproduction Organ?
The female plant reproductive organ is called the pistil, and it consists of the stigma, style, and ovary. Some might argue it has a bigger role in the reproduction process than its male counterpart.
After all, the style is what connects the pollen in the stigma with the ovules in the ovary. It’s also where the germination and fertilization take place.
What Helps Plants to Propagate Sexually?
Reproduction, whether sexual or asexual, is a natural process. So, you don’t have to worry about setting a proper environment to initiate the process.
Just ensure the anther and stigma of your flowers aren’t too far apart, and they’ll start the pollen transfer sooner or later.
What Helps Plants Grow?
If you want your baby plants to grow strong and healthy, all you have to do is provide the ideal environment. That means watering them regularly, using proper fertilizers, choosing the right type of soil, and exposing them to the right amount of light.
Of course, each plant is different. So, do extensive research before you grow new plants.
What Are the Reproductive Strategies of Different Plant Families?
As you can see, there’s more than one way for different plant families to reproduce. Each has a different process and produces different results.
Different plant types resort to a particular method depending on their surrounding environment. Here are some of the most popular reproduction strategies:
- Sexual reproduction
- Wind pollination
- Insect pollination
- Animal pollination
- Self-pollination
- Asexual reproduction
- Specialized structures
How Do Araceae Plants Reproduce?
Some plants use special structures/strategies to reproduce. In the case of the Araceae family plant, they use pheromones (scents) to attract potential pollinators.
These pheromones usually smell like rotting fish or meat. Some species use heat to spread the pheromones and provide a warm environment for pollinators.
After attracting beetles or flies, the plant traps them inside the kettle and the receptive female florets absorb their pollen.