Efficient Regeneration in Sugarcane Using Thin Cell Layer (TCL) Culture System

In vitro micropropagation using transverse thin cell layer (tTCL), very small and thin section of explant, has now emerged as a useful tool in plant tissue differentiation and regeneration. Sugarcane, a difficult-to-regenerate crop, lacks an efficient regeneration system. The present study evaluated the TCL technique as a procedure for somatic embryo production and plantlet regeneration of sugarcane plant. Explants from young leaf whorls (tTCLs) were cultivated in MS culture medium supplemented with 3% sucrose and different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and incubated under dark condition at 25 + 2 degrees C for callus formation. The innermost layer of the explants was found more responsive to callogenesis than the outer layers of the tTCLs. The explants cultured on 2.0 mg/l 2,4-D produced good-quality callus as compared to other concentrations. The calli were further evaluated for regeneration. MS medium supplemented with 2.0 mg/l BAP (Benzyl aminopurine) and 0.2 mg/l NAA (naphthalene acetic acid) was found suitable where 100% calli regenerated maximum number of shoots per callus mass (25 +/- 1.6) with highest shoot length of 6 +/- 0.5 cm. The highest number of root emergence (28.2 +/- 0.8) and maximum root length (2.8 +/- 0.09 cm) were achieved on MS medium supplemented with 4.0 mg/l NAA.