BIOLOGY [3 marks Question Answer]

Advantages of vegetative propagation are:

1. Vegetative propagation is the only method to obtain new plants in those plants where seed formation does not occur.
2. This method is cheaper, convenient and rapid method of plant multiplication.
3. It is the only method of reproduction in plants like grapes, roses, pineapple etc. which do not form viable seeds.
4. Plants raised through vegetative propagation from a single plant form a genetically uniform population called a clone.

In micropropagation, a piece of tissue such as bud or shoot tip is removed from a plant, sterilized and placed onto a culture medium. The tissue multiplies into an undifferentiated mass of cells called callus. Later it is transferred to a nutrient medium where this tissue differentiates and produces a number of plantlets. The plantlets are then transplanted into pots kept in green houses and then placed in fields to see their performance.

Plant hybridisation is a time consuming process and is carried out between two plants of different species or between two varieties of the same species.

Two parent plants are selected of which one parent has the desired characters. On the female plant, emasculation is carried out i.e. stamens are removed to prevent undesirable fertilization. Then pollen of the male plant is collected and artificially brushed on stigma of emasculated flower. The emasculated flower is kept bagged before and after fertilization to prevent any unwanted cross pollination. After pollination, fertilization takes place and seeds of desired variety are produced.