Thidiazuron-induced direct organogenesis from immature inflorescence of three date palm cultivars

Abstract

Background Inflorescence explants of date palm proved to be a promising tool for micropropagation of elite cultivars or rare males and females as organogenesis and somatic embryogenesis could be achieved. These plant materials are abundantly available every year and can be used as cheap and potent explants. Nevertheless, many difficulties could be faced in this protocol according to selection of the spathe size and age, media components, growth regulators, etc. The aim of this study was to determine the influence of various cytokinins on direct organs induction of three date palm cultivars (Selmi, Barhee, and Medjool) from immature inflorescence. An additional objective of this study was to investigate the effect of cytokinins and auxins on growth and development of Medjool cultivar. Results Various combinations of cytokinins were investigated on three date palm inflorescences as N6-(2-isopentenyl) adenine (2iP), kinetin, benzyleadenine (BA), and thidiazuron (N-phenyl-N′-1,2,3-thidiazol-5-yl urea) (TDZ). TDZ alone or in combination with BA proved to be superior for direct organogenesis in all three cultivars so that another combination of TDZ with BA was conducted. Results showed that moderate concentration of BA, with TDZ, gave superior response. Medjool cultivar response surpassed other two cultivars that made the possibility to conduct some growth regulators treatments on its multiplication and regeneration. TDZ at 0.5 + BA at 1.0 mg/l without activated charcoal seemed to enhance multiplication rate. Medium containing 0.5 mg/l of both naphthaleneacetic acid and indole butyric acid in addition to 1.0 mg/l indole acetic acid appeared to be more suitable for rooting stage of Medjool shootlets. Conclusion In this study, we created an innovation sequence of growth regulators included in nutrient media for date palm direct organogenesis from inflorescence. Organogenesis has been accelerated from immature inflorescence explants and developed to healthy plantlets which acclimatized in greenhouse.

Adventitious Shoot Regeneration from Leaf Explants in Sinningia Hybrida ‘Isa’s Murmur’

“…Kuo and Xu reported similar outcomes in species Sinningia speciosa [13,16]. TDZ is considered as optimal synthetic cytokinin for the regeneration of many plant systems [17][18][19]. In our study, abundant and dwarf shoots were induced in MS medium containing TDZ, but, even prolonging the culture time, the differentiated adventitious buds failed to elongate (Figure 2F).…”

The effects of cytokinin and plating density on protoplast culture of sunflower

“…Interestingly, we are the first to report the synergistic effects of BA and TDZ in protoplast culture. These results agree with various researchers who found that using BA together with TDZ can enhance the efficiency of cell development and regeneration of cells and tissues in other systems (Guo et al 2011;Jonoubi et al 2004;Khalafalla and Hattori 1999;Nielsen et al 1995;Taha et al 2021;Tantasawat et al 2015).…”

Indirect regeneration in Ficus lyrata Warb. and metabolite profiles influenced by nitric oxide and Plant growth regulators

“…However, compared to the control treatment, a cross-talk between auxin and cytokinin is crucial for CI and MCI since the treatments without TDZ or IBA in the medium were not morphogenic, although some had produced callus. Previous studies have well documented that TDZ has effectively stimulated de novo morphogenesis in many recalcitrant plant species, such as Phoenix dactylifera [ 18 ], Cocos nuciera [ 19 ], etc. The cross-talk of TDZ × IBA could strongly trigger cell proliferation and de novo morphogenesis in many plant species including in vitro recalcitrants, because TDZ act as a very stable CK-like substance in plant systems that effectively participates in CK metabolism and auxin translocation and accumulation in the plant [ 20 ], on the other hand, IBA is also a well-known potent auxin for cell differentiation and proliferation and is widely used in callogenesis, morphogenic callus induction, and rooting events in most plant species, including the Ficus genus [ 4 , 7 ], as observed in the current study in F. lyrata .…”