Micro propagation of dahlia plants (Dahlia variabilis). Direct and indirect organogenesis techniques

The present study was conducted for dahlia plants propagation by direct and indirect organogenesis methods. The results showed that a significant superiority of the combination of 2.0 + 2.0 mg L-1 (NAA + BA) on other combinations added to the MS medium components in the averages number of direct shoots/shoot tip and shoot length reached 10.00 shoots and 6.67 cm, respectively. While, the shoot tip cultured on MS medium supplemented with a combination 1.5 + 1.5 mg L-1 (NAA + BA) did not respond to adventitious shoot formation after eight weeks from culture. Also the results showed that the shoot tips and nodal segments developing on MS medium supplemented with 3.0 +3.0 mg L-1 (NAA + BA) were superior significantly on the hypocotyl in the percentage of the induction of callus reached 75.00%, 60.00% and 23.33%, respectively after eight weeks from culture. The shoot tip gave the largest amount of the white callus fragile. The results showed indirect shoots regeneration from the developing callus of shoot tip and hypocotyl cultured on the MS medium supplemented with 3.0 + 3.0 mg L-1 (NAA + BA) after eight weeks from culture. The two combinations of 2.0 + 2.0 and 2.5 + 2.5 mg L-1 (NAA + BA) were superior significantly on the other combination (3.0 + 3.0 mg L-1 ) in the rates of the number and length of regenerated shoots from the developing callus of shoot tip recorded 6.33, 5.67 and 5.00 shoots, and 6.67, 5.67 and 5.00 cm, respectively after eight weeks from culture. As well as the direct and indirect shoots were rooted when they cultured on half strength of MS medium supplemented with 0.6 mg L-1 IBA concentration. The dahlia plants produced by micro propagation have been acclimatized at high success percent of 100%