The vegetative propagation of strawberry plants allows dissemination of plant pathogens when infected plants are used. To avoid such pathogen transmission, especially viruses, plant merystem growing in vitro is usual. Transfer of micropropagated seedlings to ex vitro conditions, however, is a delicate process. Successful plant adaptation to ambient depends on optimum growing conditions including the rooting phase. This research was conducted at the Universidade Federal do Rio Grande do Sul and Universidade de Passo Fundo (Brazil). The effect of sucrose concentration was quantified in the culture medium over rooting of strawberry plants. Seedlings of cv. Campinas were selected during multiplication and transferred to an "MS" (Murashige & Skoog) basic medium amended with BAP (0.005 mg L-1) and different sucrose amounts (0; 15; 30; 45, and 60 g L-1). The experimental units were arranged according to a randomized block design with nine replicates, each replicate being a pot with five plants. The fresh and dry weight of leaves and roots were determined and used to calculate the content of water in plant tissues. While lack of sucrose resulted in no rooting, the concentration of 45 g L-1 provided the best root growth. Therefore, Campinas strawberry seedlings showed low photosynthetic capacity, behaving as mixotrophic or heterotrophic plants.
Fragaria X ananassa Duch.; biomass; sucrose; micropropagation
