The production of new characteristics by introducing new genes and altering the genome is called Gene manipulation. 
It includes gene splicing, use of recombinant DNA, forming of the monoclonal antibodies or PCR (polymerase chain reaction).

Gene Mechanism:

Explant  culture is an in-vitro  technique  to organotypically culture cells from a piece or pieces of tissue or organ removed from a plant or animal.

Micropropagation is a type of vegetative propagation of plants in tissue culture . In this propagation the plantlets of plants growing in tissue culture in vitro condition and then growing them out.

Protoplasts are plant cells with the plasma membrane, cytoplasm, and nucleus, which have had their cell wall removed by the action of enzymes .

Once the cell wall has been removed the resulting protoplast is spherical in shape .

Embryoid is a mass of tissue produced during culture. Formation of embryoid from pollen in tissue culture medium is due to cellular totipotency .
Cell potency is a cell 's ability to differentiate into other cell types. The more cell types a cell can differentiate into, the greater its potency. 

It is possible to produce disease-free plants through meristem culture because viruses move readily in the vascular system, which, in meristems, is absent.

Somaclonal variation is the variation seen in plants that have been produced by plant tissue culture .

Plant tissue culture specifically is also known asmicropropagation because it involves rapid multiplication of a small amount of plant material to produce more progeny.

Tissue culture is a technique of growing plant or animal cells, tissues, or organs in a sterilized nutrient/ culture medium under controlled environmental conditions.

Agar is obtained from seaweeds, and it is the most preferred gelling agent due to its advantageous properties.
It is used in some micropropagation work .

Polyamines do not promote tuber and bulb formation, but it supports root and shoot formation and also somatic embryogenesis. The promotion of bulb and tumor formation is done by jasmonic acid.