Effect of plant growth regulators, sucrose, and silver nitrate on in vitro rose flowering

Rosa hybrida (rose) is one of the most widely used species in the cut flower industry worldwide. Therefore, the micropropagation of R. hybrida L. has been extensively studied. However, studies that focus on the in vitro flowering of roses are scarce. In this study, various concentrations of 6-benzyladenine (BA) were used to promote shoot multiplication from rose stem nodes. A concentration of 0.5 mg/L of BA yielded the greatest shoot height and was then used in subsequent flowering experiments. Sucrose, BA, and silver nitrate (AgNO3) were used individually or in combination to supplement Murashige and Skoog medium for flowering experiments from shoots. The shoot height, fresh weight, dry weight, and flowering percentage were recorded after treatments. The rate of flowering was the highest (60.74%) when 1.0 mg/L BA, 1.0 mg/L AgNO3, and 40 g/L sucrose were added to the culture medium. Additionally, abnormal flowers in small shapes and unusual colors were observed. Flowering was also observed in treatments with higher concentrations; however, the flowers developed more abnormally.