THE PRODUCTION OF AZADIRACHTIN BY IN-VITRO TISSUE-CULTURES OF NEEM, AZADIRACHTA-INDICA

Callus produced from leaves of a Ghanaian strain of the neem tree, Aza dirachta indica A. Juss has been shown to produce the natural insectic ide azadirachtin when grown in a defined medium. The azadirachtin was isolated by standard procedures of solvent partition and column chroma tography monitored by supercritical fluid chromatography. Biological a ctivity was monitored with antifeedant tests using the desert locust ( Schistocerca gregaria Forsk.). The azadirachtin was identified by chro matography on three independent chromatographic systems (SFC, HPLC and TLC) and two thin-layer colour tests. It has 100% antifeedant activit y at < 0.04 mg litre(-1). The yield of azadirachtin was 0.0007% based on dry weight of callus.