In vitro conversion of alginate-encapsulated nodal segments of Rosa Hybrida L. `Kardinal´ into complete plantlets

الملخص EN

The present experiments were conducted at Humboldt University of Berlin, Horticultural Plant Systems, Germany during 2012 and 2013 seasons, to clarify the nutrient requirements for regeneration of encapsulated nodal segments of Rosa hybrida `Kardinal´, as well as define the nutrient losses from the beads during incubation on nutrient-free media.

Shoot cultures were cultivated on modified MS medium.

For encapsulation, 4 to 5 mm nodal segments were isolated 3 weeks after subculturing.

The nodal segments were put in 3% Na-alginate diluted in the modified MS medium with various sucrose concentrations (30 to 90 g l-1 ) and 0.5 to 2 mg l-1 indole-3-butyric acid (IBA).

To improve the nutrient supply, 85 µl, 95 µl or 105 µl of Na-alginate with one nodal segment was dropped in to 75 mM CaCl2 dissolved in the same media contains Na-alginate for 30 min hardening.

The results showed that already after 24h incubation on the water-agar-medium more than 90% of nitrate was diffused out of the beads.

The reduction of wateragar-medium volume from 25 ml to 7 ml reduced the nutrient leakage and improved the shoot formation from 40 to 90%.

The root regeneration of the encapsulated nodal segments also increased from 40% to 80% either by increasing the bead volume from 85 to 105 µl or the sucrose concentration from 30 to 50 g l-1 in the propagation medium.

The highest conversion (approximately 50%) was found after supplying 1 mg l-1 IBA and 90 g l-1 sucrose to the bead gel matrix