Question

What are the artificial methods of vegetative reproduction in plants? Give an example.

Answer 1

Hint: Asexual reproduction in plants by fragmentation followed by regeneration of specific vegetative parts of the plants.

Complete answer:
Plants can undergo both sexual and asexual reproduction. Sexual reproduction is though natural, asexual reproduction can be natural or artificial methods. Artificial asexual reproduction is usually human aided and is done in order to develop a new variety of plants that have more advantageous features than the parent plants. Artificial reproduction also known as vegetative reproduction improves the variety of plants by combining the features of two or more than two plants. Different methods of artificial vegetative propagation include:
> Tissue culture/Micropropagation: Where new plants (usually in large numbers) are grown under favorable conditions in the lab with a single part of the parental plant. This method involves culturing plant cells from different parts of the parental plant, the tissue is then nurtured in a special sterilized medium to form a mass of cells known as a callus. The callus is now grown in a special medium containing hormones required for the growth of different parts of the plant. Once the callus grows into a healthy plantlet, they are transferred to nursery under proper favorable conditions. These plantlets are allowed to grow in nursery till they become a mature healthy plant, after which they are grown in natural conditions.
> Grafting: grafting is usually done to produce novel varieties of plants that have properties or features from two different plants. This method includes cutting of the parental plant stem at an oblique angle. The upper part (stem side) from one parental plant (known as Scion) is then placed in close contact with the lower part (root side) of the 2nd parental plant (known as Stock). The two parts of the plants are placed in an angle so as to stick together very closely, they are then plastered to hold them together strongly. The vascular system of the two plants grow and fuse at the point of attachment over a period of time to form a graft. Some of the plants grown using this method include fruit plants like grapes to develop new or a better variety of pre-existing fruits.
> Cutting: This method is usually applied to plants that can grow from a part of the plant such as leaves, stem, nodes, and internodes. It is the simplest method where a portion of the plant containing leaves or stem with nodes and internodes is cut and placed in moist soil and allowed to develop roots and grow as a new plant. Some of the plants grown with this method include money plants, coleus, etc.
> Layering: Layering is a method similar to natural asexual reproduction seen in runner plants. This method involves burying a young stem attached to the parental plant (the one which can be easily bent without injury or any breakage). After some time when the roots develop from this young plant, they are separated from the parental plant and grown separately as a new plant. Plants like Jasmine and bougainvillea are usually artificially propagated using this method.
> Suckering: suckers are attached to the plants where they grow and form a dense compact mat, that prevent the plant growth by sucking nutrients from the main plant. Hence, artificial vegetative propagation involves removing these mature suckers and growing them in a new area. This not only gives us more number of plants but also helps in the proper growth of the parental plant.

Additional Information:
Natural asexual reproduction involves self-propagation adapted by plants through the formation of new plants from the pre-existing parts of the plant. Plants can propagate by natural asexual reproduction by budding or cutting or even sometimes the roots give rise to new plants. Some of the plant structures that can undergo natural vegetative propagation are runners, bulbs, rhizomes, tubers, and corms. Natural vegetative propagation in plants is the ability of the plants part to develop adventitious roots.

Note: Advantages of vegetative propagation are to grow plants with favorable traits, to develop disease or drought resistant plants, to increase the farm yield, and to develop new varieties.