This study was conducted to establish and optimise a regeneration system for agronomically
important Indian sorghum genotypes including two commercial cultivars (NSH27 and K8) of
Sorghum bicolor. Callus induction and plant regeneration were achieved on transverse thin cell
layers (tTCL) of hypocotyls from aseptically germinated seedlings of seven-day-old seedlings.
Callus response depended on the genotype, the concentrations and composition of growth
substances and number of in vitro regeneration cycles undergone by the donor plant.
Murashige and Skoog (MS) medium supplemented with 4.5-18.1 μM 2, 4-Dichlorophenoxy
acetic acid (2,4-D), 5.4-21.5 μM Naphthalene acetic acid (NAA), 5.7-22.8 μM Indole acetic
acid (IAA) and 4.9-19.7 μM Indole butyric acid (IBA) and combined with 10% (v/v) coconut
water (CW) for callus induction. The calli were cultured on MS medium supplemented with
2.2-17.8 μM 6-Benzyl aminopurine (BAP) combined with 5% (v/v) CW and addition of 2.3
μM 2, 4-Dichlorophenoxy acetic acid (2, 4-D) or 2.7 μM Naphthalene acetic acid (NAA).
Highly efficient differentiations of multiple shoot buds were initiated within four weeks after
inoculation. Root induction was achieved on half strength MS medium containing IAA (2.9-
28.5 μM). Rooted plants were successfully acclimatized and with the survival rate reaching
almost 80%. These plants grew normally without showing any morphological variation.