Callus produced from leaves of a Ghanaian strain of the neem tree, Azadirachta indica A. Juss has been shown to produce the natural insecticide azadirachtin when grown in a defined medium. The azadirachtin was isolated by standard procedures of solvent partition and column chromatography monitored by supercritical fluid chromatography. Biological activity was monitored with antifeedant tests using the desert locust (Schistocerca gregaria Forsk.). The azadirachtin was identified by chromatography on three independent chromatographic systems (SFC, HPLC & TLC) and two thin-layer colour tests. It has 100% antifeedant activity at <0.04 mg litre-'. The yield of azadirachtin was 0.0007% based on dry weight of callus.

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Bael (Aegle marmelos L. Corrêa) is an economically valuable tree species in South Asia. The ripen bael fruits are popular among people because of the delicious fruit pulp, which is ideal for making jam, syrup, and pudding. Bael possesses many medicinal values and therefore used as an ingredient in ayurvedic herbal medical preparations. The fruits, bark, leaves, seeds, and roots of bael contain bioactive compounds such as coumarin, xanthotoxol, imperatorin, aegeline, and marmeline. These compounds can provide antidiabetic, anticancerous, antifertility, antimicrobial, immunogenic, and insecticidal activities. Bael is also essential as a species for reforestation, especially in the unfertile marginal lands. Bael seeds possess a unique fatty acid (12-hydroxyoctadec-cis-9-enoic acid or ricinoleic acid), a convertible item into biodiesel. Bael is an underutilized fruit species in South Asian countries. However, numerous studies report the medically significant properties and industrially vital characteristics of bael in India. The present review focused on summarizing and discussing the essential details and potentials of bael for industrial applications towards economic development.

Micropropagated shoots were initiated from leaf explants of the neem tree, Azadirachta indica A. Juss. Regardless of their origin, shoots were successfully produced by culturing leaf explants on Murashige and Skoog medium containing benzylaminopurine (1 mg l -1 ), kinetin (0.8 mg l -1 ) and adenine sulphate (6 mg l -1 ) in complete darkness. These shoots were further multiplied on Murashige and Skoog medium containing benzylaminopurine (0.1 mg l -1 ), kinetin (0.08 g l -l ) and adenine sulphate (0.6 mg l -1 ). Within 32 weeks, 80 shoots could be produced from a single leaf explant (10 mm×10 mm). Fifty-five percent of these shoots rooted on Murashige and Skoog medium containing indolebutyric acid (1 mg l -1 ) and all of these grew on transfer to soil.A standard procedure for the micropropagation of the neem tree (Azadirachta indica A. Juss) Communicated by W. Barz

Hairy root cultures were established from stem and leaf explants of Azadirachta indica A. Juss (neem) following infection with Agrobacterium rhizogenes. Transformation was confirmed using polymerase chain reaction analysis. The cultures had a relatively fast growth rate (0.134 g dry weight day -1 ) and showed a 100-fold increase in biomass over a 4-week culture period. Both the roots and cultivation medium were antifeedant as determined by a no-choice bioassay using the desert locust, Schistocerca gregaria. Azadirachtin, nimbin, salannin, 3-acetyl-1-tigloylazadirachtinin and 3-tigloylazadirachtol were detected in the hairy roots by supercritical fluid chromatography. The cultivation medium contained 3-acetyl-1-tigloylazadirachtinin, 3-tigloylazadirachtol and desacetylsalannin.