Reproduction in Plants

It is the process by which new organisms are formed. It takes place in all living organisms present on Earth. The new organisms are formed or produced from their parents. They’re collectively known as offspring. It takes place in both plants and animals.

Various modes of Reproduction in plants

Reproduction can be carried in different ways and means depending upon the organisms and the way they’re formed. However, there are only two basic modes of reproduction that take place.

They are Asexual Reproduction and Sexual Reproduction. These modes of reproduction cover all the other broad categories of reproduction that follow.

Asexual Reproduction

In asexual reproduction, offspring or new plants are formed without the process of fertilization. In other words, the process of asexual reproduction takes place without the production of seeds.

Some of the prominent types of asexual reproduction are as follows:

1. Vegetative propagation: In this type of asexual reproduction, the offspring or new plant is formed from the vegetative parts of the parent plant. The vegetative parts of a plant include roots, leaves, buds, stems, and so on.  This mode of reproduction is rapid and more effective in comparison to plants that emerge out of the seeds. It is because they take less time to mature into parent plants. This also means that they bear fruits and flowers way before plants that are produced from fertilization. However, there is one demerit. The offspring are carbon copies of the parent plant. There is little or no variation at all in them.

2. Budding: This type of asexual reproduction is common in organisms like yeast and hydra. It is carried out by a bulb-like projection that forms on the parent plant. This bulb detaches from the cell and forms the offspring. During the process, it grows and matures into a new hydra. When it is mature enough, it forms a bud of its own and this mode of reproduction is further continued.  
3. Fragmentation: This is most commonly found in algae. The algae breaks into two daughter fragments. These are its offspring. This condition can occur only with the adequate presence of resources such as water and minerals. 
4. Spore formation: This type of reproduction is found in ferns and mosses. Spores are asexual structures that help in reproduction. When the condition is favourable, a spore develops into a new plant or offspring.

Sexual Reproduction

• Sexual reproduction refers to the creation of new plants by the process of fertilization. This also means that new plants are derived from seeds
• Seeds are a result of the fertilisation of the male and female gamete of a flower
• As it is clear, the flower is the main component of sexual reproduction in plants. It has two parts: Stamen and Pistil
• The male reproductive part of a flower consists of the Anther and the Filament. Together, they make up the Stamen
• Pollen grains are present in the Anther. They produce the male gametes in sexual reproduction
• The female reproductive part is called the pistil. It has various components. They are style, stigma, and the ovary. One or more ovules are present in the ovary
• The egg is formed in the ovule
• The fusion between the pollen grains and the egg forms a zygote in sexual reproduction
• When the flowers have either the pistil or the stamens present in them, they are called unisexual flowers. For instance, cucumber
• When the flowers have the stamens and the pistil present together, they are called bisexual flowers. For example, mustard
• The male and female unisexual flowers may be present in the same plant or different plants                           

Pollination

The process of the transfer of pollen grains from the male reproductive part (anther) to the female reproductive part (stigma) of a flower is known as pollination. It can be executed by the action of wind, water, and insects. They help in the dispersion of the pollen grains from one place to another to continue the process of pollination.

Pollination is of two types: Self-pollination, and Cross-pollination.

• If the pollen pollinates the stigma of the exact flower or another flower of the plant where the pollen grains are germinated from, it is known as Self-pollination

Examples of self-pollinating plants include wheat, barley, oats, rice, tomatoes, potatoes, apricots and peaches. Many plants that are capable of self-pollinating can also be cross pollinated.

• If the pollen of one flower attains the stigma of another flower of the identical kind, it is called Cross-pollination

Examples of plants that use wind for cross pollination include grasses, catkins, dandelions, maple trees, and goat’s beard.

Fertilisation: The process of fusion of the pollen grain with the egg is known as fertilisation. The fused cell is called a zygote. The zygote later evolves into an embryo. This forms an important part of sexual reproduction.

Formation of Seed and Fruits: Post fertilisation, the ovary formulates into a fruit. The remaining portions of the flower wither off. The ripened ovary is now the fruit. The seeds are produced via the ovules. The seed has an embryo present in a shielded seed coat.

Seed dispersal: Seed dispersal is the movement or transport of seeds away from the parent plant. It aids the plant to continue its genetics despite overcrowding while also helping the plant avoid competition for natural resources, minerals, and invade new habitats. It is performed under the action of the wind, water, and animals. They are elaborated below:

• By Wind: Light seeds that are easy to carry away by wind are taken to faraway places by this process. For instance, grass seeds, maple winged seeds, drumsticks, etc
• By Water: This is common with Coconut seeds that can float easily in water and travel to faraway places
• By Animals: Few seeds are distributed by animals.  They get affixed to the hooks or fur coats of animals and are transmitted to far-off places

Conclusion

Plant reproductive system, is sexual or asexual, by which plants reproduce. In plants, as in animals, the end result of reproduction is the continuation of a given species, and the ability to reproduce is, therefore, rather conservative, or given to only moderate change, during evolution. Changes have occurred, however, and the pattern is demonstrable through a survey of plant groups.

Reproduction in plants is either asexual or sexual. Asexual reproduction in plants involves a variety of widely disparate methods for producing new plants identical in every respect to the parent. Sexual reproduction, on the other hand, depends on a complex series of basic cellular events, involving chromosomes and their genes, that take place within an elaborate sexual apparatus evolved precisely for the development of new plants in some respects different from the two parents that played a role in their production.