Micropropagation of Blackberry (Rubus fruticosus.) cv. Karaka Black

T HIS work aimed to establish an in vitro protocol for Blackberry “Karaka Black” micropropagation. Stem node explants were experimented on three types of medium salts (WPM, MS and B5) in establishment stage. Also, three types of cytokinins were tested for multiplication i.e. BA (0.0, 0.4, 0.8 and 1.2 ppm), TDZ (0.0, 0.1, 0.5 and 1.0 ppm) and Kin (0.0, 1.0, 5.0 and 10.0 ppm). Two soil mixtures were used in acclimatization stage. Finally, the effect of passage time and number of subcultures on multiplication rate were investigated. The results indicated that WPM followed by MS medium gave the highest shoot length and leaf number. BA at 0.4 ppm, Kin at 5.0 ppm and TDZ at 0.1 ppm achieved the most preferable values for multiplication stage but the kinetin one gave the healthiest plantlets. The most microshoots got well-formed roots in multiplication phase. Consequently, rooting stage was not required. The multiplication rate slightly decreased after the 3 rd subculture and three months of culture date proved to be the most suitable passage time among subcultures. Peatmoss and sand mixture gave the highest plantlet quality during acclimatization.