Question

How can healthy potato plants be obtained from a desired potato variety which is viral infected? Explain.

Answer 1

The virus may not infect the whole potato plant. The virus does not affect the apical and axillary meristems of the plant, and hence they can be used to produce a healthy potato plant. This is generally done through a process by which a particular part of the tissue is used to give rise to a complete plant using an artificial environment.

Complete answer:
A healthy potato plant can be obtained from the desired potato variety which is virally infected through the process of tissue culture.

Tissue culture is a process by which any part/organ/tissue/cell of a plant is propagated in an artificial environment to give rise to a new plant. The new plant may even possess some desirable variations.

To grow a healthy potato, the meristems from the virally infected plant are used. The cells of the plant meristems are highly dividing. They are self-renewing stem cells that have not been differentiated yet.

The apical meristem is of 2 types – the root apical meristem (RAM) and the shoot apical meristem (SAM). The SAM gives rise to leaves and flowers, while the RAM gives rise to meristematic cells that help in the growth of the root. The cells of these two meristems divide rapidly and do not have defined end fate, which is why they can be modified and used for tissue culture.

Note: In the initial phase of tissue culture, the part of the plant that is being used is sterilized to get rid of any harmful microorganisms. In the second phase, the cells of the part are made to multiply and are kept in a medium containing growth factors, nutrients, and other reagents.
The tissue undergoes proliferation due to the enriched media and produces shoots. After this, hormones that induce root formation are introduced into the media.