Successful callusing is the most basic step in indirect organogenesis
where shoot regeneration precedes callus induction. The most widely
used explants for callusing are hypocotyls, sub-hypocotyl,
cotyledonary tissues, roots etc., via viable seeds. The seeds are
aseptically germinated on MS media followed by harvesting of
explants which are then transferred to MS media or B5 media or
white media depending on plant species, supplemented with different
combinations of cytokinines and auxins.