Plant regeneration via somatic embryogenesis in sugarcane.

Plants, regenerated from callus cultures of sugarcane (Saccharum officinarum L.) clone IJ76-316, originated through somatic embryogenesis. Callus cultures were established from primordial leaves and apical meristems on Murashige and Skoog medium (MS) supplemented with 3 mg 1(-1) 2,4-dichlorophenoxy acetic acid and 100 ml 1(-1) coconut water (MSC3). Nodular calli formed within 2 weeks of culture. Calli were maintained on MSC3 medium by transfer every 3 to 4 weeks. Somatic embryogenesis occurred after 10 weeks culture of callus on MSC3 medium. Somatic embryogenesis was also observed in cell suspension cultures initiated from calli maintained on MSC3 and then cultured in half strength MS liquid medium supplemented with 0.5 mg 1(-1) 2,4-D. Somatic embryos produced coleoptiles and shoots 2 to 4 weeks after transfer to MS medium supplemented with 100 ml 1(-1) coconut water (MSC), and produced complete plantlets within 4 weeks of further culture on half-strengh MS medium (half-MS) with 30 g 1(-1) sucrose. Calli grown on MSC3 medium, when transferred to half-MS medium containing 15 g 1(-1) sucrose, produced tiny plantlets, circa 4-10 mm, without forming coleoptiles, suggesting precocious germination of somatic embryos. The regenerates included morphological variants.