TO THE WORLD OF PLANTS

Fragmentation

Spirogyra, which is a filamentous green algae reproduces rapidly by this asexual mode of nutrients in water. The filaments breaks up into a number of short segments, due to force of water current or friction. Each segment then develops into a complete organism and the process continues. You might have noticed such green algae covering ditches or ponds as slimy green scum over large areas.

Spore formation

The spores are asexual reproductive bodies found in plant groups like fungi, mosses and ferns. If a piece of bread is kept in a warm and moist place, mass of fine thread – like structures which are the hyphae grow form the spores after they have settled on it. Spores are produced in large number and are very light and minute. Under favorable condition of moisture and temperature, they germinate in suitable medium into a new individual.

Vegetative Propagation

This type of reproduction is observe is higher plant groups. New plants are produced from vegetative parts of the parent plant like roots, stem or leaves. Thus there is no involvement of flower, the reproductive part. These specialized organs of propagation often have vegetative buds which develop into shoots. Some of these like potato and ginger also store food and are means of survival is adverse cold and drought conditions.

Runner or Stolons :

The runner arises as an axillary bud. It creeps horizontally some distance away form the mother plant, then strikes roots at the nodes and grows into a new plant. It may break off form the mother plant and grow as independent plant. The most common example is grass.

Tuber

Tuber is the swollen end of a special under ground stem. It arises for the axil of a lower leaf becomes swollen with heavy store of food material. It has on its surface a number of ‘eyes’ that grow into buds. A potato is an example of tuber.

Rhizome :

Rhizome is horizontally growing underground stem, swollen with stored food. A rhizome bears distinct nodes, internodes, scaly leaves and adventitious roots. It has buds on its surface from which grow new plants. Ginger and turmeric are examples.

Foliar Buds :

In Bryophyllum, rows of foliar buds are produced on the notch at the end of leaf margins. These buds may drop from the leaf and grow up into mew plants.

Root Tuber :

Root tubers are swollen adventitious roots. Examples are dahlia and sweet potato. These roots have food stored in them. If root tuber of sweet potato is cut into pieces and sown in well prepared soil, a new plant can be produced.

Advantages of Vegetative Propagation

☻ New plants are produced in less time ☻ The plants produced are exact copies of

the parent plant☻ Plants propagated vegetatively usually

need less attention than plants grown from seeds

Artificial Propagation

Man has taken advantage of the vegetative mode of propagation in plants and adapter them to his use in gardens and nurseries. These man-made methods are called artificial propagation. They are Cutting, Grafting and Layering.

Cutting :

Cutting is a simple procedure in which a healthy, young branch of a plant like rose and sugar cane having nodes and internodes is cut off and planted in moist soil. It produces roots and grows in to a new plant.

Grafting :

This method used in horticulture, to develop new varieties of fruits plants. In this method, a healthy stem of one plant with oblique cut surface is inserted over the cut stem of another rooted plant. It is then tied together. After some days, new braches develop that show combined feature of the two plants.

Layering:

In this method, a branch of the plant is bent towards the ground and covered by moist soil. After sometime, roots develop form the covered part. The bent branch is later cut and made to grow into a new plant. Plants like jasmine and bougainvilleas are developed by this method.

Keep it cool… by that I mean NO FIGHTING!!!

You have 1min to discuss amongst your group

Each team will get 1 Question The person asked should answer the

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