Page 119 - Science Class 07
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For example, potato which you eat is a swollen scion and starts feeding its cells. As a result, a
stem (tuber). The eyes on the potato stem new variety of the plant comes into being.
sprout and give rise to new plants.
Gra ing
Culms
Reproduc on in Potato
Stems–cu ngs with joints in them are buried
Vegeta ve Propaga on by Leaves in the soil in this method. In due course, a plant
Some plants mul ply by their leaves. Such plants grows out of the joint. Rose-plants, sugarcane
plants, cac and baugainvillea grow in this
are bryophyllum, begonia, etc. New plantlets
manner.
develop from the edge of these plants. When
they come in contact with the soil get detached Layering
from the leaves and grow into a new plant. In this method, a branch of a plant is bent
towards the ground and buried into the soil.
A er some me a new root develops from the
buried branch. Jasmine plants grow in this
manner.
Reproduc on in Bryophyllum
ARTIFICIAL PROPAGATION
Man felt encouraged to see plants grow
through vegeta ve reproduc on and invented
some methods of ar ficial propaga on.
Layering
These methods are as:
Tissue culture
Gra ing
A growing point is taken from a shoot p of a
In it, a cu ng (scion) of one plant is placed plant and its cells are separated from each
over the stump (stock) of the other plant and other. They are placed on a jelly with nutri ve
both of them are ed together. A er some hormones in it. It makes the cell split into a
me, the stock accepts the cell-property of the group of cells that developed roots and a small
Science-7 119
