High-efficiency somatic embryogenesis and plant regeneration in brinjal (Solanum melongena L.) var. Mattu Gulla

The organogenesis protocol was established for a unique brinjal (Solanum melongena L.) variety, “Mattu Gulla”, which has a distinct size, color and flavor. The objective of this study was to develop a reliable and efficient protocol for the initiation and maturation of somatic embryos into plantlets. The explants were cultured on Murashige and Skoog medium augmented with 2,4-dichlorophenoxyacetic acid (2,4-D) (1.0 mg/L) and benzyl aminopurine (BAP) (1.5 mg/L) for callus initiation. The developing calli (45-days old) were transferred onto an MS medium augmented with plant growth regulators to determine the embryogenic potential of the explants. The proportion of embryogenic callus was higher in hypocotyl-derived calli (HC) with indole butyric acid (IBA) (1.5 mg/L) and BAP (1.0 mg/L with 2,4-D and thidiazuron (TDZ) (1.0 mg/L) than in cotyledon and leaf-derived calli. The embryo initiation was recorded on the 23^rd day after subculture from HC with the 2,4-D and TDZ (1.0 mg/L) combination, and germination was recorded. The somatic embryos developed from cotyledon-derived calli showed the highest number of plantlets and a significant percentage of ex vitro survival. In contrast, the lowest number of plantlets was noted from the embryos of hypocotyl-derived calli and ex vitro survival of plantlets. Under greenhouse conditions, the acclimatized plantlets thrived and produced fruits with viable seeds. The established protocol in this study should serve as a platform for large-scale somatic embryogenesis and micropropagation of plantlets. The somatic embryo-based manipulation should be exploited as a biotechnological tool in crop breeding and improving desired agronomic traits.