In vitro Optimization of Protocol for Micropropagation in Cordyline [Cordyline terminalis (L.) Kunth]

Abstract

Investigation on “In vitro Optimization of Protocol for Micropropagation in Cordyline (Cordyline terminalis (L.) KUNTH)” was accomplished at the Biotechnology-cum-Tissue Culture Centre in Baramunda, Floriculture and Landscaping Department of Odisha University of Agriculture and Technology, Bhubaneswar. Explants were collected from nodal segments and shoot tips, out of which nodal segments of Cordyline were found to be an ideal explant for enhanced released of axillary buds, direct organogenesis and indirect organogenesis. The best sterilization treatment was 0.1% HgCl2 for 10 minutes(T8) recording low fungal contamination (3.33%), no percentage of bacterial infection (0.00 %), low death (3.33%), significantly higher aseptic percentage (96.67%) and significantly higher survival percentage (93.33%). The nodal segment explants collected in drier months (November and December) recorded highest survival rate (95%). Full MS medium resulted in direct organogenesis in all the 8 treatments of 0.1% HgCl2 with less duration for bud emergence (19.00 days), less time for shoot growth (28.33 days), significant length of shoot (3.10 cm) and leaves number (9.00) producing greenish leaves and shoots. In vitro rooting was seen successfully in full MS medium with better root formation in 47.33 to 54.67 days, number of roots/explant (2.67 to 5.33) and root length (5.07-7.67) giving rise to lateral, long, slender, creamish roots. Indirect organogenesis was seen in all 11 treatments of MS media supplemented with BAP, NAA and 2,4-D. Best treatment for callus growth was MS medium + BAP 1.0 mg/l + NAA 0.5 mg/l recording maximum callus percentage (83.33%) in a short duration of time (11.33 days) with callus intensity (4.40), callus index (367.00) and produced best result with soft and creamy white callus. Besides, NAA in the medium induced callus formation at the base before root induction giving rise to thick, short and creamish colour roots. Hardening methods involved planting of micropropagated plants in cocopeat + sand followed by regulation of light intensity, humidity, temperature resulting in 50% survival after 4 weeks. Successful generation of this protocol will encourage large-scale plantlets production in the future, benefit hi-tech farmers and entice entrepreneurs for commercialization.