Optimizing Micropropagation Protocol for Rosa hybrida cv. Eiffel Tower with Improved in vitro Rooting Ability

Document Type : Original Article

Authors

1 Department of Ornamental Plants and Landscape Gardening, Faculty of Agriculture, Assiut University, Egypt

2 Department of Ornamental Plants and Landscape gardening, Faculty of Agriculture, Assiut University, Assiut, Egypt

3 Horticulture Department, Faculty of Agriculture, New valley branch, Assiut University, Egypt

Abstract

In vitro propagation techniques were studied to establish a protocol for rapid and mass production of Rosa spp. cv. Eiffel Tower, an important and endangered cultivar. Several experiments were conducted through a two-stage procedure: multiplication stage and rooting of microshoots stage.  For multiplication, the best results were obtained when nodal segments were cultured on MS medium supplemented with BAP at 1mg/l and/or Kinetin at 0.5 mg/l. The highest shoots number (3.17 shoots/explant) was obtained when 0.5 mg/l BAP was added to the medium. Kinetin at 0.5 mg/l produced the highest shoot number/explant (3.67 shoots), and shoot length (3.67 cm). The interaction between BAP at 1 mg/l plus kinetin at 0.5 mg/l gave the highest shoot number/explant (4 shoots). For rooting, the best interaction effect on rooting percentage (61.00%), highest number of roots/shoot (5.12) and root length (3.33 cm) were observed when the shoots were cultured on hormone-free MS medium and pH level was adjusted to 5.5. Moreover, adjusting the medium pH to 5.5 formed roots faster in 17.67 days followed by medium with pH level 4.5 (18 days).  The medium with pH at 5.5 supplemented with 50 g/l sucrose produced the highest significant value of rooting (85%) and enhanced root formation in 7.5 days. The rooted plantlets were transplanted into the potting substrate and successfully acclimatized in the laboratory then transferred to the field with a survival rate of 55%. After 6 month, the plantlets reached ~ 22 cm in length and 5.50 leaves/plant

Keywords