Research Article Details

Abstract

In several mature trees like Margosa, long- term conservation through seeds is not possible as they are highly susceptible to various pathogens and are spoiled within a few weeks during storage. Micropropagation too is difficult due to lack of any suitable juvenile explant and presence of polyphenols. Most of the explants such as leaf, stem pieces and petiole segments are recalcitrant for in vitro differentiation. Genetic improvement of such species can not be performed till a suitable regeneration protocol is established. Anthers being more juvenile as compared to other explants, respond quickly to in vitro regeneration techniques under suitable physico-chemical environment. In the margosa tree ( Azadirachta indica A, Juss, Family Meliaceae) young anthers containing sporogenous tissues produced sufficient amounts of organogenic callus on various media supplemented with plant growth regulators in proper concentration and combinations. The browning of the callus could be inhibited with the help of Polyvinylpyrrolidone (PVP), or activated charcoal or L-cysteine. Whenever needed multiple shoots were differentiated by subculturing yellowish green nodular callus masses on media possessing one cytokinin (BA or Kn) and one auxin (IAA, NAA, or IBA) in combination. The regeneration potential of the callus was maintained for several years. The morphogenetic response from subcultured callus masses was in the form of caulogenesis, rhizogenesis and embryogenesis according to composition of culture media. The regenerated plants showed minimum variability in their morphological characters.