Embryogenesis and organogenesis of Brucea javanica (L) Merr. and its relationship to secondary metabolite production

Abstract

This present work was undertaken to determine appropriate methods of somatic embryogenesis as well as organogenesis in Brucea javanica (L.) Merr. which may prove useful for commercial plantation. Hypocotyl explants excised from 10 day old seedlings in 1/2MS medium without hormonal supplement differentiated into protocorm-like bodies which after routine subcultured, developed into somatic embryos. The embryo with its define shoot and root segregated itself from the ground tissue and germinated into a complete vigorous plantlet. However, the production rate of embryogenesis was quite low due to abnormal fusion along its longitudinal axis. Organogenesis could be induced up to the multishoot stage with the exogenous supply of BAP and NAA at 2.0 and 1.0 mg/l respectively. However, rooting of in vitro grown shoots was difficult. In this particular case, somatic embryogenesis was condidered a more favorable method for commercial production. Both natural and tissue culture-derived samples were analyzed for their quassinoid and alkaloid contents. TLC analysis of chloroform extracts indicated that the three active bruceolides bruceine-A, bruceine-B hydrate, and bruceine-C were absent in all tissue culture-derived samples. From TLC analysis, at least three different alkaloids, Rf 0.57,0.53, and 0.22 were detected in tissue culture-derived sample. These were different from that detected in chloroform extract of the fruit.