The aim of this work was to evaluate the in vitro potential of multiplication of the four main raspberry cultivars used in Brazil: Autumn Bliss, Batum, Dorman Red and Heritage. A commercial micropropagation protocol was used. The explant desinfestation was carried out in solution of alcohol and sodium hypochlorite. The meristem culture was carried out in semi-solid MS medium with 1 mg L-1 BAP, 0.01 mg L-1 ANA and 0.1 mg L-1 AG3; the explant multiplication in MS medium with 0.8 mg L-1 BAP and 15 mg L-1 iron sulphate; and the rooting in ½MS medium with 0.1 mg L-1 ANA, always at 25±4ºC, 20 µE m-2 s-1 and 16 hours photoperiod. Sixty meristems of each cultivar were used, evaluating the multiplication rate and the level of contamination, vitrification and oxidation during the phases of in vitro establishment (60 days), multiplication (six subcultures of 40 days) and rooting (30 days). The raspberry cultivars studied showed high genetic variability concerning in vitro multiplication rate. The estimated number of plants obtained per meristem for the described micropropagation system was of 56664 for 'Autumn Bliss', 6692 for 'Heritage', 1942 for 'Batum' and 696 for 'Dorman Red'. The quantification of this in vitro variability response is important for planning the plant production in commercial laboratories.
Rubus ideaus L.; meristem; micropropagation; plant production
