Reproduction


   
 
Asexual Reproduction (Contd...)
Regeneration
 
Regeneration of new plants from the vegetative parts of the parent plant is called vegetative propagation or vegetative reproduction. Vegetative propagation is done with the help of vegetative parts such as roots, stem or leaves. These parts may also be variously modified for vegetative propagation.
 
Natural vegetative propagation is of different types based on the vegetative organ involved.
 
Vegetative Propagation by Roots
 
Roots of some plants develop new plants either by directly producing shoots or producing buds. Shoots are produced by roots of woody plants like Dalbergia, Murraya etc. Adventitious buds are formed on the roots of plants like sweet potato, dahlia, asparagus, tapioca, etc. These buds detach from the root and develop into new plants.
 
 
                     Root Tubers of Dahlia
 
Vegetative Propagation by Stem
Stem has nodes and internodes. The nodes develop leaves. In the axils of the leaves buds develop called the axillary buds. They develop into new plants on detachment from the parent plant or even when the stem portion remains attached.
 
There are different types of stems for vegetative propagation. They are:
 
Subaerial Stems
 
The branches that arise from the stem which is very close to the surface of the ground break off from the parent plant and develop new plants.
 
These branches are classified as follows:
 
Runners - For example, strawberry, grass, etc.
 
 
                                  Strawberry Runner
 
Suckers - For example, mint, Chrysanthemum
 
 
      New Plants from Sucker of Mint
 
 
Vegetative Propagation by a Sucker of Chrysanthemum
 
Stolon - For example, gooseberry, jasmine, etc.
 
 
Offset - For example, Eichhornia (water hyacinth), Pistia, etc.
 
 
Vegetative Propagation by an offset of Water Lettuce (Pistia)
 
Underground Stem
 
The portion of the stem that is underground, in some plants, serves two functions. It tides over unfavourable conditions by storing food and becoming dormant and then germinating with the help of axillary buds when there are favourable conditions.
 
The underground stems may be variously modified into the following kinds:
 
Tubers
 
The stem is swollen and the nodal regions are called the eyes.
 
For example: Potato
 
 
The Formation of Axils and Development of Aerial Shoots in Potato
 
Each eye has scaly leaves and axillary buds which develop into new plants when the tuber is planted.
 
Rhizomes
 
The stem is also swollen but it is branched. The scaly leaves are bigger.
 
For example: Ginger, Turmeric etc.
 
 
                  Diagrammatic Structure of an Iris (Rhizome)
 
Rhizomes also give rise to new plants from the axillary bud.
 
Bulb
 
The stem is very small and disc-like.
 
For example: Onion, Garlic, Lilies, etc.
 
 
                   Diagrammatic Section through a Dormant Bulb
 
From the stem arise scaly and fleshy leaves which bear buds in their axils.
 
Corm
 
The stem is very similar to tuber but they do not have definite shape.
 
For example: Amorphophalus, Colocasia, Gladiolus, saffron, etc.
 
 
Vegetative Propagation by Underground Corm
 
Vegetative Propagation by Leaves
 
This is not very common and is seen in plants such as Bryophyllum.
 
 
Totipotency Exhibited by Bryophyllum
 
It has succulent (fleshy) leaves and adventitious buds are present at the margins of the leaves. These buds fall off and grow into new plants.
 
  
     
   
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