Callus induction was tried with stem explants (nodal region from third node from top of canopy) harvested on 30 days after seed germination from in situ control and supplementary ultraviolet-B irradiated (UV-B = 2 hours daily @ 12.2 kJ m-2 d -1 ; ambient = 10 kJ m-2 d -1 ) three varieties of black gram viz. VAMBAN-3, NIRMAL-7 and T-9 to assess their viability for germplasm storage. Callus induction failed to occur in control and UV-B exposed VAMBAN-3, NIRMAL-7 and T-9 stem explants. However, stem explants from unstressed NIRMAL-7 proliferated axillary bud. The present study proves that nodal stem explants from the three varieties of black gram taken for the experiment are not suitable for germplasm conservation for cultivation in UV-B elevated environment.
