Indirect somatic embryogenesis in sweet orange cv. “Mosambi”

Abstract

This study was carried out to standardize a reliable protocol by using different explants (epicotyl, cotyledon, and root), plant bioregulators (PBRs), and carbon sources on indirect embryogenesis during 2019-2022. Among the treatments tested, T4 (MS + 2,4-D (1.5 mg L-1) + BAP (1.0 mg L-1) + ME (500 mg L-1)) proved best for callusing (90.89 %), callus fresh weight (0.83 g), turgid weight (0.84 g) and dry weight (0.08 g) as compared to others. In terms of callusing (83.72%), callus fresh weight (0.67 g), turgid weight (0.68 g), dry weight (0.05 g) and callus water content (11.28 %), explants epicotyl (E) showed its superiority over others. Similarly, the treatment combination T4 × E surpassed others in callusing potential. Embryogenesis (59.09%) and germination (33.61%) were best in T7 (MS + BAP (2 mg L-1) + NAA (0.1 mg L-1) + ME (500 mg L-1)). Among the different carbon sources, 5% glycerol supplemented with T7 proved best in inducing the highest number of somatic embryos/callus mass (73.26), embryogenesis (65.27%), and plantlet formation (68.77%). Therefore, the standardized protocol can be used for indirect embryogenesis for different genotypes of sweet orange.