Stimulation of rooting of Citrus embryoids by gibberellic acid and adenine sulphate

Abstract

Embryoids obtained from subcultured ovular callus of the Shamouti orange (Citrus sinensis) were grown on Murashige and Tucker nutrient medium (BM) in the presence and absence of gibberellic acid (GA2), adenine sulphate (ADS) and combinations of these. Both GA2 and ADS stimulated significantly the rooting of small embryoids with unorganized tissue, and larger embryoids with partially developed root zones. Only large embryoids with fully developed root zones rooted well on BM but better on BM+GA2+ADS. Rooting was best on media containing 1 to 5 mg per 1 ADS, and these two combined. The optimum sucrose concentrations were 5 to 6 per cent. Shoot formation on embryoids prior to rooting completely inhibited rooting which is otherwise enhanced by GA2+ADS. Filter-sterilized and autoclaved GA2, showed similar activity in rooting. © 1974 Oxford University Press.