When vegetative parts of plants i.e., roots, stems, or leaves give rise to new plants, the process is called vegetative reproduction or vegetative propagation.
It takes place naturally, and can likewise be brought about artificially.
Process of Vegetative Propagation
Vegetative propagation involves vegetative or non-sexual plant structures, whereas sexual propagation is achieved through gamete production and subsequent fertilization. In non-vascular plants such as mosses and liverworts, vegetative reproductive structures consist of gemmae and spores. In vascular plants, vegetative reproductive structures include roots, stems, and leaves.
Vegetative propagation is made possible by meristem tissue, frequently found within stems and leaves along with the tips of roots, which contain undifferentiated cells. These cells actively divide by mitosis to allow prevalent and rapid primary plant growth. Specialized, permanent plant tissue systems likewise originate from meristem tissue. It is the ability of meristem tissue to continually divide that permits plant regeneration needed by vegetative propagation.
Natural Vegetative Propagation
Vegetative propagation occurs naturally in numerous methods.
- Bulbs are short underground stems surrounded by thick, fleshy leaves that contain stored food. Adventitious roots emerge under the base of the bulb while shoots emerge from the top of the base. Tulips, onions, and lilies reproduce by bulbs.
- Corms are short and swollen underground stems containing stored food. Buds are present at the top of the corm. From a bud, the shoot grows and forms a new plant. Dasheen and garlic reproduce by corms.
- Roots are horizontal underground stems with scale leaves. There are enlarged portions called nodes on the rhizome. Buds are produced at nodes. The buds present on the upper surface of the rhizome give rise to shoot. The lower surface area of the root produces adventitious roots. Ginger, ferns, and water lilies reproduce by rhizomes.
- Stem Bulbs are the enlarged parts of an underground stem (rhizome). There are aggregations of tiny buds in the form of “eyes” along the surface of the root. Each bud develops into the shoot that grows up and likewise produces roots. Potatoes and yams reproduce by roots.
- Suckers are lateral stems near ground level. A sucker grows underground from some distance and after that shows up, producing a new plant. Mint and Chrysanthemum reproduce in this way.
- Vegetative propagation by leaves is not typical and is seen in plants such as Bryophyllum (Pather chut). This plant has fleshy leaves and adventitious buds exist at the margins of leaves. When a leaf falls on the ground, the buds grow into new plants.
Artificial Vegetative Propagation
Gardeners and farmers use artificial approaches to vegetative propagation to increase the stock of a plant. The following two are the most common approaches to artificial vegetative proliferation.
- Cuttings
In this technique, cuttings might be taken primarily from the stems or roots of the parent plant. These cuttings should have a meristematic region from which growth can occur. When cuttings are positioned in suitable soil and under favourable conditions (enough nutrients, water, and sunshine), they form roots and shoots. Roots and shoots grow and become a plant identical to the parent plant from which the cuttings were taken. Roses, ivy, and grapevines are propagated by stem cuttings. Sweet potato is a bigger root.
Farmers place it in damp sand or soil till it produces numerous plantlets. Then the plantlets are eliminated and planted. This procedure is utilized to produce lots of plants from a single plant. All new plants are precisely the same. This synthetic vegetative propagation has been very beneficial on sugar cane plantations.
- Grafting
In grafting, a piece of stem is cut from the plant and is connected with another plant with an established root system. After a while, the vascular bundles of the attached stem piece and the host plant are linked to each other.
The stem piece and the plant begin to grow together. This technique is used to propagate lots of roses, peach trees, plum trees, and various seedless fruits (including grapes).
Advantages and Disadvantages of Vegetative Propagation of Plants
Plants can reproduce asexually through vegetative propagation. This method of reproduction has some advantages and disadvantages too.
Advantages
The offspring produced through vegetative propagation are genetically similar. Therefore, advantageous characteristics can be maintained. In vegetative propagation, there is no need of any system of pollination. It assists to increase the number of plants at a rapid rate. The organs of vegetative proliferation enable lots of plants to pass over unfavourable conditions. Plants bearing seedless fruits can be grown only by vegetative propagation.
Disadvantages
The plants do not have genetic variations. Species with particular diseases can attack and this can result in damage of an entire crop.
MCQs
- What is vegetative propagation?
- A) Sexual reproduction in plants
- B) A process where vegetative parts give rise to new plants
- C) Fertilization in plants
- D) A process involving pollination
Answer: B
- Which of the following is NOT a vegetative part involved in vegetative propagation?
- A) Roots
- B) Flowers
- C) Stems
- D) Leaves
Answer: B
- What type of plant structures are involved in vegetative propagation?
- A) Reproductive structures
- B) Sexual structures
- C) Vegetative or non-sexual structures
- D) Vascular structures
Answer: C
- What allows for rapid primary plant growth in vegetative propagation?
- A) Adventitious roots
- B) Meristem tissue
- C) Rhizomes
- D) Corms
Answer: B
- In which type of plants do gemmae and spores serve as vegetative reproductive structures?
- A) Vascular plants
- B) Mosses and liverworts (non-vascular plants)
- C) Ferns
- D) Bulbous plants
Answer: B
- Which of the following plants reproduces by bulbs in natural vegetative propagation?
- A) Ginger
- B) Tulips
- C) Dasheen
- D) Mint
Answer: B
- What are corms in the context of vegetative propagation?
- A) Enlarged portions of stems
- B) Bulbous roots
- C) Underground storage organs
- D) Shoots with buds
Answer: C
- Which of the following plants reproduces by rhizomes in natural vegetative propagation?
- A) Roses
- B) Ginger
- C) Potatoes
- D) Dasheen
Answer: B
- What are suckers in the context of vegetative propagation?
- A) Lateral stems near ground level
- B) Shoots emerging from bulbs
- C) Adventitious roots on rhizomes
- D) Leaves with adventitious buds
Answer: A
- Which plant reproduces by leaves in vegetative propagation?
- A) Roses
- B) Bryophyllum
- C) Ginger
- D) Mint
Answer: B
- What is the primary purpose of artificial vegetative propagation?
- A) Enhance plant growth
- B) Increase genetic diversity
- C) Increase the stock of a plant
- D) Promote sexual reproduction
Answer: C
- Which of the following is a common method of artificial vegetative propagation?
- A) Pollination
- B) Grafting
- C) Fertilization
- D) Germination
Answer: B
- What is the role of meristematic region in vegetative propagation by cuttings?
- A) It stores nutrients
- B) It promotes flowering
- C) It allows for growth and development
- D) It produces spores
Answer: C
- Which plants are commonly propagated by stem cuttings in artificial vegetative propagation?
- A) Ginger
- B) Roses
- C) Mint
- D) Water lilies
Answer: B
- What is the purpose of grafting in artificial vegetative propagation?
- A) Enhance plant growth
- B) Introduce genetic variations
- C) Connect a stem piece to a plant with established roots
- D) Produce seedless fruits
Answer: C
- Why are offspring produced through vegetative propagation genetically similar?
- A) Due to sexual reproduction
- B) Due to cross-pollination
- C) Due to genetic variations
- D) Due to asexual reproduction
Answer: D
- What advantage does vegetative propagation have in terms of pollination?
- A) It eliminates the need for pollination
- B) It increases genetic diversity
- C) It promotes self-pollination
- D) It requires specialized pollinators
Answer: A
- Why can species-specific diseases pose a risk in vegetative propagation?
- A) Genetic variations protect against diseases
- B) The plants lack resistance
- C) Genetic diversity enhances immunity
- D) Vegetative propagation is immune to diseases
Answer: B
- In which type of plants can seedless fruits be grown through vegetative propagation?
- A) Bulbous plants
- B) Vascular plants
- C) Non-vascular plants
- D) Any type of plant
Answer: B
- What is the major disadvantage of vegetative propagation in terms of genetic variation?
- A) Limited adaptation to environmental changes
- B) Increased susceptibility to diseases
- C) Rapid plant growth
- D) Lack of genetic variations
Answer: D
- Which plant part is used for grafting in artificial vegetative propagation?
- A) Leaves
- B) Roots
- C) Stems
- D) Flowers
Answer: C
- What is the purpose of cutting placement in suitable soil during artificial vegetative propagation by cuttings?
- A) To prevent growth
- B) To promote flowering
- C) To form roots and shoots
- D) To enhance nutrient absorption
Answer: C
- What is the common outcome of placing cuttings in suitable soil and under favorable conditions?
- A) Formation of seeds
- B) Rapid shoot growth
- C) Development of new plants
- D) Formation of flowers
Answer: C
- What is the role of adventitious roots in natural vegetative propagation by roots?
- A) Absorb nutrients
- B) Enhance photosynthesis
- C) Support the stem
- D) Produce new shoots
Answer: A
- Which of the following is a method of natural vegetative propagation by stems?
- A) Grafting
- B) Suckers
- C) Cuttings
- D) Corms
Answer: B
Summary
In this tutorial on Vegetative Propagation, we explored the process where roots, stems, or leaves of plants give rise to new plants, known as vegetative reproduction. This phenomenon occurs naturally and can also be induced artificially. The tutorial is divided into sections covering the process of vegetative propagation, natural methods, artificial approaches, and the advantages and disadvantages associated with this mode of plant reproduction.
Key Points:
- Process of Vegetative Propagation:
- Involves vegetative or non-sexual plant structures.
- Meristem tissue, with undifferentiated cells, enables rapid plant growth.
- Natural Vegetative Propagation:
- Bulbs, corms, roots, stem bulbs, suckers, and leaves are natural methods.
- Each method involves specific plant structures for reproduction.
- Artificial Vegetative Propagation:
- Common methods include cuttings and grafting.
- Cuttings involve taking parts from stems or roots, while grafting connects stems to plants with established root systems.
- Advantages:
- Genetically similar offspring for maintaining advantageous characteristics.
- No need for pollination.
- Rapid increase in the number of plants.
- Suitable for plants bearing seedless fruits.
- Disadvantages:
- Lack of genetic variations.
- Vulnerability to species-specific diseases, risking damage to entire crops.
This comprehensive tutorial provides insights into the diverse methods of vegetative propagation, both in nature and through human intervention, highlighting its benefits and drawbacks in the context of plant reproduction.