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 the 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 of vegetative propagation to increase the stock of a plant. The following two are the most common approaches to artificial vegetative proliferation.
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.
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.
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.
The plants do not have genetic variations. Species particular diseases can attack and this can result in the damage of an entire crop.