الفهرس 
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Abstract
Nodal segments were taken from the middle portion of the shoots were used for the establishment of in vitro grown shoots under aseptic condition as a source of explants (Leaf and internode) for callus production and shoots as shown in (Fig. 3.2.), washed in running tap water for half an hour and immersed in 15% sodium hypochlorite with 2 drops/100 ml of Tween 20 for 15 min with continuous shaking. They were then rinsed 3 times with autoclaved
distilled water, explants were sectioned to 2 cm segments containing two to three nodes and cultured in jars, each containing 250 ml, jars containing 50 ml of MS media (Murashige and Skoog,1962) with 3% (w/v) sucrose and 2 mg/l-1
6-benzylamino purine (6-BAP) and 0.1 mg/l1
α-naphthalene acetic acid (NAA) and 1 g/l-1activated charcoal (AC) and 7 g/l-1
agar to induce axillary buds to form new axillary shoots. The pH of all tested media was adjusted to 5.7 before autoclaving at 121°C and 118 kPa, a pressure of 15 psi for 20 minutes. All cultures were incubated between 4-6 weeks at 25±1°C under continuous fluorescent light (1000 lux)
with (16 h/ 8 h/d) light/dark cycle, during this period; sub culturing was done every 21 days on the same media. The cultures were set up at four separate experiments as follow.
Leaves and internodes, established from plantlet of D x grandiflorum, were used for induction of callus. For the leaves, medium-sized leaves were selected and cut into several small parts, and the middle area was chosen for planting with a length of a 2 cm. As for the internodes were sectioned to small sections each section was 2 cm segments containing two to three nodes and cultured in jars. Five replications were used per each treatment, each
containing one explant; all treatments were cultured in 125 ml jars containing 25 ml of the tested media. MS media supplemented with 30 g/l-1
sucrose, 0.1 mg/l-1 NAA and solidified
with 7 g/l-1
agar. Different concentrations of 6-BAP (0.1, and 0.2 mg/l-1) and 2,4- Dichlorophenoxy acetic acid (2,4-D) (0, 0.5, 1, 1.5, and 2 mg/l-1) were added to the media before autoclaving. MS basal media without plant growth regulators (PGRs) was used as a
control. Five replicates were used per each treatment. All cultured were incubated for 8 weeks
at 25±1°C under continuous fluorescent light (1000 lux) with (16 h/ 8 h/d) light/dark cycle.
After 8 weeks, callus fresh and dry weights (g) were recorded.