Exchange of germplasm is carried preferably through shoot tip culture because they are

Somaclonal variation appears in plants:

What is the cause of embryo formation from pollen grains in a tissue culture medium?

Select the correct sequence for the production of somatic hybrid plants in somatic hybridization.
$I -$ Isolation of protoplasts
$II -$ Digestion of cell wall
$III -$ Regeneration of somatic hybrid plants
$IV -$ Isolation of cells
$V -$ Fusion of protoplasts of two different varieties
$VI -$ Formation of hybrid protoplasts

In the initial stages of protoplast culture,sorbitol or mannitol is added:

Which of the following substances is $NOT$ used for the formation and maintenance of callus in plant tissue culture?