In vitro Regeneration and Biohardening of Soybean (JS335) Variety

An efficient protocol for in vitro regeneration of half seed explant with embryonic axis of soybean and biohardening of in vitro regenerated plantlets were standardized. For organogenesis, MS medium supplemented with cytokinins BAP (15 M) and TDZ (15 M) in combination with NAA (1, 5 and 10 M) or IBA (1, 5 and 10 M). Among the concentrations, TDZ (15 M) + NAA (10 M) was found to be best for highest percentage (86 %) of shoots as well as the maximum number of shoots (20.60.88) and length of shoots (9.00.78 cms). The best response for maximum number of roots (18.60.88) with root length (2.90.18 cms) was noticed in the combination of TDZ (15 M) with IBA (5 M). The plantlets were transferred into the papercups and inoculated with Bacillus subtilis to enhance the survival of regenerated plantlets. The maximum survival (85 %) was recorded in the plantlets treated with B. subtilis (0.6) of Optical Density at 600 nm with maximum number of shoots (26.00.7) and length of shoots (21.00.5 cms) and maximum number of roots (12.30.4) and root length (2.7.01 cms) when compared with untreated plantlets. This protocol may be used in mass multiplication of elite soybean genotypes through tissue culture and genetic transformation studies.