Development of an efficient protocol for ‘Brazos’ blackberry in vitro multiplication

Abstract

In vitro culture is a very important technique in plant mass propagation, as well as an auxiliary tool to germplasm conservation and gene transfer. The present study developed an efficient multiplication protocol for 'Brazos' blackberry. Here, its multiplication ability was evaluated using in vitro shoots grown on medium supplemented with different growth regulators: thidiazuron (TDZ), 6-benzylaminopurine (BAP), kinetin (KIN), zeatin (ZEA) and isopentyladenine (2iP) in two concentrations (5 and 10 μM) plus growth regulator free medium and five different basal media: Murashige and Skoog (MS), Murashige and Skoog with half-strengthened salts (MS/2), Anderson (AND), Quoirin and Lepoivre (QL) and woody plant medium (WPM). Number of shoots formed, shoot length and number of leaves per shoot were evaluated. Shoots were evaluated and subcultured three times, at every four weeks into a fresh medium. Among the different cytokinins, BAP in both concentrations was the best for shoot multiplication with 4.4, 6.1 and 7.9 shoots per explant with 5 μM and 4.3, 4.7 and 4.8 shoots per explant with 10 μM, in the three subcultures. Thidiazuron was not viable because of shoot malformation and great callus formation. Among the medium salts tested, MS medium was slightly better, reaching 3.9, 4.3 and 2.5 shoots per explant in the first, second and third subculture. The results of this investigation indicate that blackberry multiplication is viable and represents a potential technique for rapid and efficient multiple shoot induction and plantlet recovery. In vitro multiplication and a culture medium MS supplemented with BAP 5 µM can be recommended for 'Brazos' blackberry.