Abstract
Acacia ehrenbergiana Hayne, an indigenous legume of the Middle East is an abiotic stress resistant nitrogen fixing legume which possesses valuable medicinal and economic properties. It has great potential to be used as reclaiment of denuded barren lands if only it could be propagated at a large scale. However, low seed germination and high seedling mortality apprehend its uses. Use of tissue culture technology could overcome these limitations but unfortunately there is no report describing micropropagation protocol for this species. The present study thus describes the first successful report on micropropagation of A. ehrenbergiana and also discusses the possible physiological and molecular reasons responsible to make particular culture condition, type and concentration of PGR most effective. It uses cotyledonary node explants cultured on PGR augmented Murashige and Skoog (MS) medium. A maximum of 90.3 +/- A 2.4 % of culture showed regeneration on benzyl adenine (BA) (10 mu M) supplemented medium, maximum number of shoots (7.3 +/- A 0.15) were obtained on BA and NAA (0.1 mu M) supplemented medium. Culture conditions were optimized by manipulation of pH of the medium, 5.8 being the best. Sub-culturing up to three passages for multiplication and thereafter induction of in vitro rooting was found to be most economical both in terms of time and money. Rizogenesis was observed best in MS medium supplemented with IBA (5.0 mu M). 80 % of the rooted plants were successfully transferred to the natural condition under the sun.