This study was carried out in the laboratory of cells and plant tissue culture at Department of Horticulture and Landscape Design, College of Agriculture and Forestry, Mosul University, to propagate Petunia hybrida
cv. “grandiflora doppia miscuglio” in vitro
through multiplication of shoot tips and nodes produced from axenic seedling by culturing them on MS medium supplemented with (0.0, 0.5, 1.0, 1.5, 2.0) mg/l BA. Shoot produced from multiplication stage were cultured on MS medium containing (0.0, 0.25, 0.5, 0.75, 1.0) mg/l IBA. In addition, this study included culturing leaf explants and petioles on MS medium supplemented with different concentrations (0.0, 0.5, 1.0) mg/l BA and NAA (0.0, 0.1, 0.2, 0.3) mg/l. The results indicated that highest shoots number 9.3 shoots/explants with 3.0 cm length were obtained from culturing shoot tips on MS medium supplemented with 2.0 mg/l BA as compared to nodes which gave 10.2 shoots/explants with 2.9 cm length when cultured on MS medium containing 1.0 mg/l BA after eight weeks. Highest rooting percentage 100% with highest roots number 12.4 were obtained from shoot tips that produced during
multiplication stage on MS medium containing 0.25 mg/l IBA after four weeks. Highest fresh weight of callus was obtained from culturing leaf explants and petioles on MS medium supplemented with a combination of 1.0 mg/l BA and 0.2 mg/l NAA which reached to 1.237gm. and 1.346 gm. respectively. Leaf explants that cultured on MS medium supplemented with 1.0 mg/l BA and 0.1 mg/l NAA produced shoots with percent of 10% while highest percentage of shoots production 20% with 1.0 shoot/explant were achieved from differentiation of petiole callus cultured on MS medium supplemented with 1.0 mg/l BA and 0.2 mg/l NAA after 8 weeks. All plantlets produced from these experiments were acclimatized and transferred to field successfully.