Influence of exogenous polyamines and plant growth regulators on high frequency in vitro mass propagation of Gloriosa superba L. and its colchicine content

An efficient in vitro mass propagation technique was successfully developed for Gloriosa superba L. using callus induced from non-dormant corm buds. Sulfuric acid treatment was optimized to break seed dormancy which resulted in high frequency germination. Proficient callus induction and proliferation was observed when the explants were grown on modified MS (mMS) medium supplemented with 2,4-D (1.5 mg l(-1)) and Kin (1.0 mg l(-1)). The combination of BA (1.5 mg l(-1)) and NAA (0.6 mg l(-1)) induced highest multiple shoot formation frequency. When the medium was supplemented with putrescine (15 mg l(-1)) the explants responded with highest multiplication frequencies of in vitro shoots. The regenerated shoots showed superlative response for in vitro rooting on mMS medium fortified with IBA (1.0 mg l(-1)), IAA (0.6 mg l(-1)) and 15% coconut water. Colchicine content of both field grown and in vitro raised plants were compared using HPLC and it was found that leaf samples from field grown plants showed 0.00241 mg/ml colchicine compared to methanolic extract from Spermidine, Spermine and Putrescine treated leaf samples which showed relatively higher concentrations of colchicine (0.00265 mg/ml, 0.00356 mg/ml and 0.00569 mg/ml) respectively. Putrescine treated in vitro plants showed only a marginal increase in colchicine content compared to spermine and spermidine treated plants. This established protocol will help in both pharmaceutical and conservation aspects of G. superba to meet its commercial demands in the future.