Asexual Reproduction in Plants : Artificial Methods
Artificial vegetative propagation:
Vegetative methods offer many advantages. As the new generation produced by asexual reproduction is exactly same as the parent (clone), the good qualities of a race or variety can be preserved indefinitely. If plants have poor viability or prolonged seed dormancy, then vegetative propagation is a rapid, easier and a less expensive method of multiplying plants.
Methods of Artificial Vegetative Propagation Used in Agriculture and Horticulture:
The process of growing plants using artificial method is called artificial propagation.
In this method a young branch is bent and pressed into moist soil. After some time roots develop from the covered part. This is called a layer.
Now the branch can be cut from the parent and a new plant is produced .
This method is used to propagate plants such as jasmine, black raspberries.
In this method a healthy young branch with a few nodes and internodes is cut off and most of its leaves are removed.
Now the cut end is stuck into some good moist soil. Care is taken that the soil remains moist. The cutting will then develop roots, and grow into a new plant.
This method is used to propagate plants like rose, sugarcane and pineapple.
This is a common method employed in horticulture to develop new varieties.
It involves removing a twig or bud of plant (called the scion) and inserting or tying it over the cut stem of another plant (called the stock). The stock should have an extensive root system under the soil.
The two cut surfaces are bound together and the joint is covered with wax to prevent evaporation and to stop infection. The tissues of the stock and scion join together to form one plant, During this process the stock supplies essential nutrients to the scion.
By this method desirable features of any two plants can be combined.
For example a high-yielding variety of a fruit is grafted to another of the same species for known for its resistance to diseases, to get a disease resistant, high-yielding variety.
Many varieties of mango (Alhanso), for example, are produced by grafting.
This is a modern method of vegetative reproduction.
In this method a piece of tissue is cut from the plant the removed tissue is called explant. The explant is kept in nutrient medium under controlled condition. This tissue grows into mass of cells called callus. Cells of callus are separated and each cell can give a new plant. These cells are called plantlets. Now the plantlets are grown in pot of soil.
Plants like chrysanthemum and orchids have been propagated by this method.