Callus proliferation and in vitro organogenesis of Gloriosa superba : An endangered medicinal plant

Abstract

Gloriosa superba L. an important medicinal plant has become endangered due to over exploitation, as the tubers are rich source of an alkaloid, colchicine. Poor seed germination and tuber dormancy restricts it multiplication and thus the germplasm available is very less. So, there is urgent need to develop a protocol for its conservation and commercial propagation. Only 10-15% of seeds germinated after three weeks following cold treatment. Best shoot multiplication in sprouted tubers (88.67%) was observed in MS supplemented with 2.0 mg/l BAP, 0.5mg/l Kn and 1.0 mg/l GA₃ with 8.7±0.18 average number of shoots per explant. Long and healthy roots were observed in MS medium supplemented with 2.0 mg/l IBA resulting in 84.50% of root growth and average of 7.47±0.29 roots per explant. Organogenesis was obtained from embryogenic callus in MS medium supplemented with BAP, Kn and IBA. Further subculturing of embryogenic callus in MS medium containing 2,4-D, BAP and Kinetin resulted in globular structures while addition of only BAP resulted in heart shaped somatic embryos on the callus. Studies are on way to further use this protocol to increase the content of various alkaloids, with special emphasis on colchicine.