Effects of Some Antioxidants on in Vitro Rooting of Apple Shoots

Abstract

In vitro-proliferated shoots of `Delicious' and `Starkspur Red' apples (Malus domestica Borkh.) were submitted for 1 week to root induction in the dark with their basal parts in liquid medium containing 1.5 μ m IBA and 43.4 m m sucrose. The shoots were transferred to root initiation and root elongation medium made up of plugs wetted with half-strength Lepoivre salts. When antioxidants, such as PVP, GH, 2-Me, and DIECA, were added to the liquid induction medium, the percentages of rooting usually decreased. In contrast, if the antioxidants PVP and citric acid were added in the initiation-elongation medium, the percentages of rooting increased. The results agree with the finding of other researchers who proposed a rapid increase in peroxidase activity during root induction followed by a fast decline during rooting initiation as a marker for good rooting responses. Moreover, the use of antioxidants both in induction and in initiation-elongation had no effect on number and length of roots. Chemical names used: polyvinylpyrrolidone-40 (PVP); glutathione reduced (GH); 2-mercaptoethanol (2-Me); diethyldithiocarbamic acid, sodium salt trihydrate (DIECA); N- (phenylmethyl) 1 H- purin-6-amine (BA); 1 H- indole-3-butyric acid (IBA); gibberellic acid (GA 3 ).