Shoot organogenesis and plant regeneration in Agave hybrid, No. 11648

Abstract

The effects of explant type and the combination and concentration of plant growth regulators on callus induction and shoot regeneration in Agave hybrid No. 11648 were examined. Shoot tip and immature leaf segments were cultured on Murashige and Skoog (MS) medium supplied with different concentrations of benzyladenine (BA), at 0.2–3.0mgl−1, and α-naphthalene acetic acid (NAA), at 0.1–1.0mgl−1, or 2,4-dichlorophenoxyacetic acid (2,4-D), at 0.2–2.0mgl−1 for callus induction. The highest rate of light yellow-green, compact and nodular-like calli was formed on the MS medium supplemented with 2.0mgl−1 BA in combination with 0.2mgl−1 NAA, with 93.2% of shoot tips producing a compact, light yellow-green and nodular-like callus. The calli derived from the different explants were subcultured on Schenk and Hildebrandt (SH) medium (300mgl−1 ammonium nitrate, 2267mgl−1 potassium nitrate, 353mgl−1 potassium dihydrogen phosphate, 3mgl−1 glycine, 1.0mgl−1 thiamine hydrochloride (B1), 1.0mgl−1 pyridoxine hydrochloride (B6), 1.0mgl−1 niacin, 200mgl−1 inositol) containing different concentrations of BA, NAA and indole-3-butyric acid (IBA) for shoot induction. Shoot organogenesis was achieved when the callus tissue derived from shoot tips was transferred to SH medium. Maximum organogenesis was obtained with 5.0mgl−1 BA in combination with 0.1mgl−1 NAA and 0.1mgl−1 IBA, yielding 98.0% shoot induction frequencies. Regenerated shoots were rooted on growth regulator-free MS medium, with an average number of 5.39 roots per shoot, and a length of 8.44cm per root within 30 days, and acclimatized in a greenhouse, with 98.57±1.43% survival. This is the first report of plant regeneration from Agave hybrid No. 11648 shoot tips.