In-vitromass propagation of the near-extinctMammillaria san-angelensisSánchez-Mejorada

Abstract

Summary The genus Mammillaria includes many valuable species some of which are near to extinction. The beautiful white-spined M. san-angelensis has been reported to be extinct. Using the related species M. haageana in preliminary trials, the in-vitro mass propagation from young seedlings of the near-extinct M. san-angelensis has been achieved. Morphogenetic responses in M. haageana and M. san-angelensis were similar. The results were influenced mainly by two factors: the presence of the cytokinin 6-benzyladenine (BA) and the origin of the explant. Callus formation rarely occurred; however, shoots and multiple shoots were obtained when tip (apical) explants were exposed to different concentrations of BA and naphthalene acetic acid (NAA). Only multiple shoots were apparent when lateral explants were exposed to similar experimental conditions. Mass regeneration was most successful when lateral explants were subjected to three treatments: BA alone at 0.1 mg l⁻¹; BA 0.1 mg l⁻¹ combined with NAA at 0.01 and BA 1.0 mg l⁻¹; or in combination with NAA 0.01 mg l⁻¹.