Influence of in vitro preconditioning with carbohydrates during the rooting of microcuttings on in vivo establishment

Abstract

The influence of in vitro conditioning and rooting of microcuttings with different concentrations of sucrose (0–6%) and types of carbohydrate (sucrose, glucose, maltose, fructose and sorbitol) on their in vivo establishment was investigated using Potentilla fruticosa cultivar ‘Tangerine’ and Ficus lyrata. Maximum values for shoot height, fresh weight and dry weight were obtained for both species 4 weeks after transferring to in vivo conditions when previously conditioned with 2 or 4% sucrose. Plantlet establishment was high (85–97.5%) and only declined (15–62.5%) when 0% sucrose was used. Shoot height, fresh weight and dry weight of Potentilla were greatest when conditioned with sucrose, glucose or maltose. Similar results were obtained for Ficus except that maltose gave significantly less shoot growth than glucose or sucrose. For both species sorbitol gave the least growth followed by fructose. Plant establishment was high (85–100%) for all carbohydrate types tested. The ways in which the carbohydrate in the culture medium may influence the quality of acclimatized plants and interact with the morphology of the cultured species are discussed.