In vitro callus induction from adult tissues of peach (Prunus persica L. Batsch)

We describe an efficient protocol for callus induction from adult tissues of Prunus persica (L.) Batsch. Three different commercial peach genotypes, Early May®, Zise May®, and UFO-3®, plus three other genotypes from hybrid crosses performed in February 2006, PS108, PS208, and PS708, were used in the study. Thirteen explant treatments were tested using nine different plant parts. Murashige and Skoog and woody plant medium salts were assayed with several concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D), kinetin (KN), and thidiazuron, and two different photoperiods were tested, a 16-h photoperiod or continuous darkness. In terms of the quantitative response, two parameters were assessed: the number of d to callus induction and relative callus growth recorded after 30 d. Woody plant medium supplemented with 2,4-D and KN significantly increased the rates of callus induction in the majority of treatments. And no significant differences among the P. persica genotypes were found. The explants derived from stem and calyx produced up to 85 and 96% callus induction, respectively. The protocol described here could be used for efficient callus induction in a range of Prunus spp.