The Effects of Some Antioxidants on the Growth of Excised Date Palm (Phoenix dactylifera L.) Roots Cultured in Vitro

Abstract

<jats:p>The objective of this investigation was to study the effects of some antioxidants on the growth and elongation of in vitro-cultured date palm roots. Several trials were conducted to determine the antioxidant and the concentration of antioxidants used in date palm tissue culture. Three types of antioxidants were tested—activated charcoal, polyvinylpyrrolidone (PVP), and sodium metabisulfite (NA<jats:sub>2</jats:sub>S<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub>)—in various concentrations, singly, or in combinations. The medium used for root culture consisted of MS salts mixture, 1/2 modified White's organics, 60% sucrose, 0.004% inositol, 240 mg adenine sulfate/liter, 1.0 mg 2,4-D/liter, and 2.0 mg kinetin/liter. pH was adjusted at 5.7 ± 0.1. Concentrations of activated charcoal tested (in g<jats:sup>–</jats:sup>liter<jats:sup>–1</jats:sup>) were: 0.0, 1, 2, 3, 4, 6, 8, 10, and those of PVP (in g<jats:sup>–</jats:sup>liter<jats:sup>–1</jats:sup>) were: 0.0, 5, 10, 20, 40 (with or without 4 g activated charcoal/liter). NA<jats:sub>2</jats:sub>S<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub> concentrations (in mM) tested were: 0.0, 0.2, 0.4, 0.8, 1.6 (with 4 g activated charcoal/liter). The addition of activated charcoal to the culture medium of date palm roots is of vital importance. Four grams per liter gave the best growth and elongation, and there was no significant difference between it and 10 g<jats:sup>–</jats:sup>liter<jats:sup>–1</jats:sup>. No growth or elongation occurred in the control. PVP, however, significantly inhibited growth and elongation of cultured roots at all concentrations tested. NA<jats:sub>2</jats:sub>S<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub>, however, stimulated growth and elongation at 0.2 mM. Higher concentrations inhibited growth and elongation.</jats:p>