Vol. 12, Issue 6 (2023)

Author(s):
Rocky Thokchom, Soumen Maitra, SS Gantait, K Lily Devi, S Sanjay Singh, Jenita Thokchom, Laishram Hemanta, M Preema Devi, Lakshmi Hijam, Y Ranjana Devi and P Kumar Singh

Abstract:
Leaf base explants of Iris ensata were cultured in MS basal medium containing different plant growth hormones. MS supplemented with 2,4-D (1.0 mg/l) and TDZ 0.1 mg/l) showed earlier callus initiation (25.30 days) in greater percentage of explants [96.67% (79.69%)] and produced higher callus weight at both 15 (0.373g) and 30 (2.961g) days after culture. Regenerated calli when cultured in MS + GA3 (2.0 mg/l) + BAP (1.0 mg/l) recorded earlier regeneration (29.20 days) with greater percentage of explants [99.70% (86.97%)], greater micro shoot length (8.64 cm) and leaf length (7.00 cm); while MS+GA3 (2.0 mg/l) + BAP (2.0 mg/l) produced maximum number of micro shoots per culture (16.30) with broadest leaf (1.32 cm). MS supplemented with 2.0 mg/l BAP yielded maximum number of leaves per micro shoot (11.70). In vitro regenerated micro shoots when cultured in MS medium containing IBA (1.0 mg/l) + NAA (1.0 mg/l) reported earlier root initiation (26.07 days) with higher number of roots per plant (9.07) having greater length (9.32 cm). Percent of rooted micro shoots were found highest [99.62% (86.51%)] when tried with MS + IBA (1.5 mg/l) + NAA (1 mg/l). Diameter (1.019 mm) of regenerated in vitro roots was found higher with MS + IBA (2.0 mg/l) + NAA (1.0 mg/l). A mixture containing equal proportion of vermiculite and vermicompost (v/v) resulted greater survivability [86.85% (68.69%)] in shorter duration (12.43 days) during subsequent acclimatization of in vitro regenerated plantlets of Japanese Iris. Culture of explants in hormone free MS basal medium showed least response in all growth and development aspects in vitro. Least percent of acclimatized plantlets [55.42% (48.15%)] was obtained from the hardening medium containing equal proportion of garden soil and vermicompost.