Desiccation of callus enhances somatic embryogenesis and subsequent shoot regeneration in sugarcane

332-334Callus cultures were established in three commercial sugarcane varieties, viz., CoJ 64, CoJ 83 and CoJ 86, from spindle leaf segments on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D; 4 mg/L) and 6-benzylaminopurine (BAP; 0.5 mg/L). The calli were sub-cultured on MS+2,4-D (2 mg/L)+BAP (0.5 mg/L)+agar (0.8% w/v) medium (control) and MS+2,4-D (2 mg/L)+BAP (0.5 mg/L)+agar (1.6% w/v) medium (treatment) to study the effect of desiccation caused by double agar on somatic embryogenesis. Per cent somatic embryogenesis observed in treatment-calli of sugarcane varieties CoJ 64, CoJ 83 and CoJ 86 was 90, 90.63 and 89.66, respectively; while in control-calli the corresponding figures were 66.67, 64.52 and 63.33. Likewise, shoot regeneration from desiccated calli on MS+BAP (0.5 mg/L) medium was also higher over non-desiccated control, i.e., 84.27, 86.52 and 83.13% as compared to 54.35, 56.25 and 50.38%, respectively in CoJ 64, CoJ 83 and CoJ 86. Thus, this fairly simple double agar medium provided an alternative method for improving somatic embryogenesis and, hence, regeneration frequency of sugarcane callus