In vitro propagation of a cut flower variety Muscari armeniacum Leichtlin ex Baker through direct bulblet proliferation pathways

Abstract

Muscari armeniacum is one of the important ornamental cut flowers in floriculture industry, which is native to Southern Europe, North Africa, Western Asia and Asia Minor. In this study, bulb explants (basal plate of bulb having meristems), bulb scales, and leaf segments from in vitro derived bulblets were cultured in Murashige and Skoog (MS) medium with different plant growth regulator concentrations and combinations to assess their effects on different bulblet organogenesis pathways. The results demonstrated that cytokinin in combination with auxin is required for both axillary and adventitious bulblet regeneration. Benzyladenine (BA) combined with α-naphthalene acetic acid (NAA) showed significant effects compared to other growth regulator combinations tested. The 4.0 µM BA + 2.0 µM NAA was found to be the best for axillary bulblet formation from bulb explants. Likewise, bulb and leaf segments showed the best response in adventitious bulblet organogenesis when they were cultured in BA-NAA combinations. Out of several concentrations of BA with NAA, 4.0 µM BA + 1.0 µM NAA was optimum for adventitious bulblet regeneration. Bulblets, properly isolated from both axillary and adventitious proliferation systems, showed maximum percentage of rooting on half strength MS medium containing 2.0 µM indole-3-butyric acid (IBA). However, all the auxins at more than 2.0 µM concentration showed reduced root formation through either callus formation at the base of shoots or malformation of roots. All the in vitro regenerated plantlets were successfully acclimatized under ex vitro environment with 60% survival rate using garden soil.