In vitro zygotic embryo germination and propagation of an endangered Boswellia serrata Roxb., a source of boswellic acid.

This study aims to establish an efficient protocol for development of seedlings of an endangered medicinally important forest tree Boswellia serrata Roxb., for mass plantation and consistent supply of salai guggul. The green mature fruits served as source of seeds. The excised green zygotic embryos were cultured on Gamborg (B5), McCown and Loyd (WPM) and Schenk and Hildebrandt (SH) media fortified with different concentration of sucrose and on Murashige and Skoog (MS) medium containing 3 % sucrose, polyvinylpyrrolidone (PVP) (0-300 mg l(-l)), Gibberellic acid (GA3), Indoleacetic acid (IAA), Naphthaleneacetic acid (NAA), Indole-3-Butyric acid (IBA) or 2,4-dichlorophenoxyacetic acid (2,4 D) and 6-benzylaminopurine (BA) or kinetin (Kin) individually. The highest frequency of embryo germination (96 %) and conversion into seedling was obtained on MS medium containing 3 % sucrose together with 200 mg l(-l) PVP; other media were either inferior or induced abnormalities in the seedlings including callus formation from the zygotic embryos. Fully developed seedlings could be successfully established in soil with about 94 % survival. The embryos from mature dry seeds did not respond for germination in any of the experiments. In conclusion, selection of zygotic embryo from green mature seeds and their in vitro germination is important for propagation of B. serrata.