Influence of basal vitamins, growth regulators, and explants on in vitro organogenesis from synthetic seeds of Citrus jambhiri Lush.

Abstract: An efficient shoot and root organogenesis protocol has been developed from synseeds derived from various explants of Citrus jambhiri Lush. Optimum synseeds were developed using sodium alginate (0.5-0.75%) in 1.0% CaCl₂ solution. Shoot organogenesis was examined under various basal vitamin mediums (MS Nitsch and MSB5) supplemented with various concentrations of adenine sulfate (ADS) and 6-benzyl amino purine (BAP) from different explants such as cotyledonary junction, shoot tip, and nodal explants. The synseed regeneration response ranged between 60-100% among the vitamins, cytokinins and explants used. The number of shoots per synseeds was higher (13.4) in MSB5-BAP (1.5 mg L^-1), followed by 12.8 in MSN-ADS (2.0 mg L^-1), 11.2 in MSN-ADS (1.0 mg L^-1), and 10.8 in MSB5-ADS (1.0 mg L^-1) from the synseeds developed using 0.75% sodium alginate. The mean number of roots per explant was higher (4.2) in ½MSN+IAA (1.0 mg L^-1). Similarly, the mean root length was higher (5.2 cm) in ½MSN+IAA (0.5 mg L^-1) followed by 4.2 cm in ½MSN+IAA (1.0 mg L^-1). Regenerants derived from synseeds have shown no somaclonal variations, confirming that the plantlets are true-to-type to their parental progenies. The encapsulated plantlets showed >90% survivability while transferred at Kachai village, Manipur, India. The results of the present study encourage the use of various vitamin mediums and explants for large-scale propagation of C. jambhiri through synseeds.