In vitro shoot growth of Brugmansia × candida Pers

Abstract

The objective of this study was to improve the growth of in vitro shoot cultures of Brugmansia × candida 'Creamsickle'. Several mineral nutrient experiments were conducted to determine the effect of NH 4+, NO 3-, K +, FeSO 4/EDTA, ZnSO 4, MnSO 4, and CuSO 4 on quality, leaf width and length, size and weight of shoot mass, and shoot number. The experiment to determine the levels of NH 4+, NO 3-, and K +, was conducted as a 2-component NH 4+: K + mixture crossed by [NO 3-] and resulted in an experimental design free of ion confounding and capable of separating the effects of proportion and concentration. The results of the NH 4+-K +-NO 3- experiment revealed a region in the design space where growth was significantly improved; the region generally had lower total nitrogen and lower NH 4+:K + ratios than MS medium. The experiments to determine the appropriate levels of Fe, Zn, Mn, and Cu were conducted at six log levels ranging from 0 to 1 mM. Of the four metal salts tested, MnSO 4 had the least effect on in vitro shoot growth and its concentration was reduced from 0. 1 mM (MS level) to 0. 001 mM. CuSO 4 had large effects on in vitro shoot growth and was increased from 0. 0001 mM to 0. 001 mM. A 2-level factorial of NH 4+-K +-NO 3-, FeSO 4/EDTA, and ZnSO 4 was conducted and several formulations identified for their improvements of quality and growth. In addition to the changes to MnSO 4 and CuSO 4, these formulations were characterized by lower levels of NH 4+, K +, NO 3- and Zn, and higher levels of FeSO 4/EDTA. Overall, several nutrient formulations were identified as superior to MS medium for growth of in vitro shoot cultures of B. 'Creamsickle'. © 2011 Prof. H.S. Srivastava Foundation for Science and Society.