RESEARCH ARTICLEAn efficient in vitro shoot regeneration from leaf petiolar explantsand ex vitro rooting ofBixa orellanaL.- A dye yielding plantArifullah Mohammed1,2&Kishore K. Chiruvella2&Nima D. Namsa3&Rama Gopal Ghanta2Received: 11 February 2015 /Revised: 2 April 2015 /Accepted: 8 April 2015#Prof. H.S. Srivastava Foundation for Science and Society 2015AbstractBixa orellanaL. (Bixaceae) is a multipurpose treegrown for the production of commercially important dyes. Inthe present study, an efficient, reproducible protocol was de-veloped for direct plant regeneration from in vitro derivedpetiole explants ofBixa orellanaL. Murashige and Skoogmedium (MS) supplemented with 2-isopentenyl adenine(9.8μM) and naphthalene acetic acid (10.7μM) wasfound to be optimum for production of high frequency ofshoot organogenesis. Subculturing of the shoots onto the freshMS medium containing similar concentrations of 2-iP(9.8μM) and NAA (10.7μM) produced elongated shoots.Elongated shoots when placed onto MS medium supplement-ed with 1.7μM indole-3-acetic acid and 14.7μM 2-iP pro-duced optimal rooting. Rooted plantlets were acclimatizedand transplanted to the field successfully. Histological inves-tigation revealed the origin of shoot primordia, from sub-epidermal cells of petiole explants. The regeneration protocoldeveloped in this study can be useful for mass in vitropropagation