Question

Artificial induction of roots on stems before it is separated from the parent plant for propagation is called:
A. Root-stem joint
B. Plant tissue culture
C. Grafting
D. Layering

Answer 1

Hint: All of the mentioned options are a type of artificial asexual reproduction. We have to find out a type of asexual reproduction in which the artificial induction for the propagation is done on the parent plant itself.

Complete Step by Step Answer:
Artificial methods or Horticulture are man-made methods of vegetative methods.
Plant tissue culture is a laboratory technique used to maintain or grow plant cells on the growth medium of known concentrations under sterile conditions. This is widely used to culture cells to make their clones or genetically mutate them to know their function. Our genes of interest can also be transferred in them to get or to study the protein of interest.

Grafting is the most common method of artificial vegetative propagation. Dicotyledonous plants have cambia. Two closely related dicotyledonous plants can be used for grafting. The supporting portion of one plant called stock and a twig of another plant called scion are joined to form a composite plant. For example, scions of high-quality roses are grafted on wild rose rootstock. During grafting, callus formation is observed which unites stock and scion. This callus is produced by cambium and this is why grafting is successful in dicots and unsuccessful in monocots as monocots don’t have the cambium.

In layering, a portion of an aerial stem grows roots while still attached to the parent plant and then detaches as an independent plant.

Hence, the correct option is D.

Note: In layering, a soft basal branch is defoliated in the middle where a small injury or cut is given (oblique cut, V-shaped cut, removal of ring of bark). The injured defoliated part is buried in the soil to develop adventitious roots. The pegged-down branch of the plant is called the layer. There are different kinds of Layering.