Callus induction and plant regeneration from anthers of Azadirachta indica

The combination of 4.0 ppm alpha-naphthaleneacetic acid (NAA) with 2.56 ppm kinetin in Murashige and Skoog (MS) basal medium was found to be the best for callus formation from yellow-coloured neem (Azadirachia indiea) anthers (a day prior to anthesis) after 30 to 35 days of incubation. The green nodular callus developed into shoots/shoot buds on MS medium supplemented with 1.0 ppm of benzylaminopurine (BAP). Prolonged incubation on this medium increased the length of shoots with green shiny leaves. The addition of 0.25 mg l(-1) silver nitrate produced longer shoots with good growth and bigger and broader leaves; induction of new buds appeared after three months of incubation. The excised shoots developed healthy roots upon transfer to half-strength MS medium containing 1.0 ppm indole-3-acetic acid (IAA) alone or in combination with 0.01 ppm kinetin (which responded better) after 15 to 20 days of incubation.