Asexual reproduction
•    In asexual reproduction new plants are obtained without production of seeds or spores. A single parent can produce offsprings, which are genetically and morphologically similar to their parent and called as clone. It occurs by different methods :

1. Vegetative propagation
(i)    It is a type of asexual reproduction in which new plants are produced from roots, stems and leaves. For eg. by stem in potato and ginger, by roots in sweet potato, raddish and by leaves in bryophyllum. Since reproduction is through the                         vegetative parts of the plant, it is known as vegetative propagation. 
(ii)    Plants produced by vegetative propagation take less time to grow and bear flowers and fruits earlier than those produced from seeds. The new plants are exact copies of the parent plant, as they are produced from a single parent.

(iii)    Cut branch of rose or champa with node called as cutting. When these cuttings are buried in the soil than from node new leaves arises and from buried part roots arises.

Figure: Stem-Cutting of Rose

(iv)    Over the stem, multicellular out growths appear called buds. Buds, which develops into flower called floral buds. Some buds are present in axil of leaves, which develop into shoots. These buds are called vegetative buds. A bud consists of a short            stem around which immature overlapping leaves are folded. Such vegetative buds can give rise to new plants.

(v)    Over a fresh potato, some scars are found having buds. These scars are called “eyes”. A piece of potato having eye when buried in soil can produce a new plant.

Figure: Potato Plant Sprouting from an ‘eye’

Similarly ginger and turmeric can be grown.

Figure: Ginger with new plants sprouting from it 

(vi)    Bryophyllum (Sprout leaf plant) has fleshy leaves with serrated margin. Over margins buds are present, when leaf falls on a moist soil, each bud can give rise to a new plant.

Figure: Leaf of Bryophyllum with buds in the margin

(vii)    The roots of some plants can also produce new plants. For e.g. sweet potato, Dahlia, raddish, carrot etc. The pairs of cacti plant, when get detached from the main plant body can produce in plants.

Advantages of Vegetative fropagation
    •    Plants produced by this method take less time to grow and bear flowers and fruit faster than those produced from seeds.
    •    Seedless plants can be obtained.
    •    Plants produced are exact copies of the parent plant. No variations are present.

2. Budding

(i)    Yeast is a single-celled microscopic organism.
(ii)    In yeast small bulb-like projection coming out from the yeast cell is called a bud. 
(iii)    The bud gradually grows and gets detached from the parent cell and forms a new yeast cell. 
(iv)    The new yeast cell grows, matures and produces more yeast cells. Sometimes, chain of bud arises from single yeast cell. 
(v)    If this process continues, a large number of yeast cells are produced in a short time. Yeast can be easily grown in sugar solution. Yeast is commercially used in bakery etc.

3. Fragmentation

(i)    Slimy green patches in ponds, or in other stagnant water bodies can be easily seen. 
(ii)    These are the algae i.e. spirogyra or pond silk. 

(iii)    When water and nutrients are available algae grow and multiply rapidly by fragmentation. 
(iv)    An alga breaks up into two or more fragments. 
(v)    These fragments or pieces grow into new individuals. This process continues and they cover a large area in a short period of time. e.g. Spirogyra.

4. Spore formation

(i)    The fungi on a bread piece grow and form spores which are present in the air. When spores are released they keep floating in the air. As they are very light they can cover long distances.
(ii)    The spores are asexual reproductive bodies. 
(iii)    Each spore is covered by a hard protective coat to withstand  unfavourable conditions such as high temperature and low humidity. So, they can survive for a longer time. 
(iv)    Under favourable conditions, a spore germinates and develops into a new individual. Plants such as mosses and ferns also reproduce by means of spores.

Activity : To observe spore formation in bread mould. 

•    Take a slice of bread and slightly moisten it.
•    Leave it in air for 3 days.
•    Observe after 3 days with a magnifying glass. You will notice fine thread-like structures (hyphae) and small spherical structures (sporangia) on long stalks are seen in Fig:
•    Now, take a spherical structure on a slide in a drop of water and put a cover slip on it.
    On observed under the microscope.
    You will see very small rounded bodies called the spores.

Artificial Methods of Vegetative Propagation
    Vegetative propagation carried out by human beings is called artificial propagation. There are several methods of artificial propagation. Two of the methods are stem cutting and grafting. 
•   Stem cutting is generally used in plants like rose, champa, sugar cane and bougainvillea. A stem cutting is a short piece of a branch of a plant having a node. This cutting when placed in the soil under suitable      conditions develops roots and leaves. Finally the complete plant develops.

•    Layering is done when the other propagation methods are unsuccessful and only a few plants are needed. It is a method in which roots develop on a shoot or branch that is still attached to the parent plant.           The stem is cut off from the parent plant only after it has rooted. Layering is generally used in plants like honeysuckle, rhododendron and forsythia.
•    Grafting is a very common method of artificial vegetative propagation in fruit plants like mango. New varieties can be developed by this method. In this method, the root portion is taken from one plant. This is        called the stock. The stem portion, with several buds, is taken from another plant called the scion. 
    The scion is taken from a plant which has the desired features that are intended to be introduced in the root portion. The ends of the stock and the scion are obliquely cut and firmly tied together. In this manner,      a new plant variety is developed.