Studies regarding the micropropagation of some blackberry cultivars.

Our paper presents the results of the application of a micropropagation protocol developed at theFruit Research Station Cluj, in Rubus fruticosus cultivars ‘AŒaAanska bestrna’, ‘Chester Thornless’, ‘LochNess’ and ‘Navaho’. For the in vitro multiplication stage, Murashige & Skoog (MS) media supplementedwith 0.3 and 0.5 mg/l BAP and gelled with starch were used. Direct ex vitro rooting was carried out.The shoots regenerated in vitro in the multiplication stage were rooted ex vitro in two experimentaltreatments: float hydroculture and floating perlite beds. In cultivars ‘Loch Ness’ and ‘Chester’ 0.5 mg/lBAP yielded good results regarding in vitro proliferation and multiplication rates and the regeneratedshoots were vigorous, suitable for ex vitro rooting and acclimatization. In cultivars ‘Navaho’ and ‘AŒaAanskaBestrna’ the optimal BAP concentration was 0.3 mg/l, which ensured normal plantlet development. Theexperimental treatments with 3 and 4 microcuttings / vessel gave good results, whereas the ones with 1and 2 microcuttings / vessel did not yield satisfactory results regarding growth and proliferation. Wheatstarch was successfully used as a gelling agent in all the cultivars. In cultivar ‘AŒaAanska bestrna’ potatostarch gave very good results regarding in vitro proliferation. In the direct ex vitro rooting experimentsfloating perlite gave good results in all the cultivars. In cultivar ‘AŒaAanska bestrna’ ex vitro rooting in floathydroculture gave relatively poor results, with rooting percentages around 60 %.