Developing micropropagation protocol for black mulberry ( Morus nigra L.)

Abstract

This study aimed to develop a suitable micropropagation protocol for black mulberry ( Morus nigra L.), which cannot be easily clonally propagated like the other mulberry species. Clonal propagation of this species is gaining importance due to its health benefits and utilization in pharmacology. The effects of the culture media and cytokinin concentrations on the micropropagation of black mulberry were investigated. Single-axillary bud explants grown on Murashige and Skoog medium, Driver and Kuniyuki walnut medium, and Nas and Read medium (NRM) containing 0.25 mg L -1 of benzyladenine (BA) plus 0.01 mg L -1 of indole-3-butyric acid (IBA) were compared to cultures grown on NRM with thidiazuron (TDZ), meta-Topolin (mT), or BA at concentrations of 1.25, 2.5, 5.0, or 7.5 mg L -1 plus 0.01 mg L -1 of IBA. The culture medium had a significant effect on the shoot length, which was greater on the NRM (3.3 shoots per explant) compared to the other media. Shoot multiplication was similar on all of the tested media. TDZ negatively affected shoot formation and triggered rosette shoots and/or large callus formation. BA and mT promoted both shoot proliferation and elongation. Around 84% of the micro shoots rooted and the rooted shoots were successfully acclimatized to ex vitro conditions.