Micropropagation of strawberry (Fragaria x ananassaDuch.). Effect of mineral salts, benzyladenine levels and number of subcultures on the in vitro and field behaviour of the obtained microplants and the fruiting capacity of their progeny

Abstract

SUMMARYThe effects of different salt formulations and benzyladenine levels on in vitro culture of strawberry cvs Douglas and Chandler were studied. While the N30K salt formulation is adequate for both cultivars, BA requirements differ. Best results on rooting were obtained with either the Knop or N30K salt formulations. Addition of 500 mg I' activated charcoal also enhanced rooting; in contrast, high BA levels during multiplication decreased the rooting capacity of shoots. Micropropagated plants showed a higher runner production capacity than their control counterparts. This increase in quantity was not linked with decreased quality. Salt formulations, BA levels (1.48-4.44 uM) and the number of subcultures (1-8) seemed not to affect the behaviour of plants in the nursery. No adverse effects on total fruit production or fruit size could be associated with the mineral formulations used during the in vitro phase, high BA concentrations adversely affected total fruit production although differences between t...