Leaf chlorosis is regarded as a main problem which has been frequently reported in micropropagation of Rosa hybrida cultivars. In this study the effect of silver nitrate and glutamic acid in culture medium was evaluated for the alleviation of leaf chlorosis. Hence different concentrations of glutamic acid (0, 2, 4, 8, 12 mg/l) and silver nitrate (0, 25, 50, 75, 100 mg/l) were added to VS culture medium containing BAP (1 mg/l) and NAA (0.1 mg/l) as plant growth regulators at shoot multiplication stage. The results showed significant differences in all characters as follows: shoot number, green leaves percentage (%) and shoot length (cm) (P≤0.01). Based on the results silver nitrate in lower concentrations was effective in controlling leaf chlorosis of the regenerated plantlets. The maximum percentage of green leaves (97.99%) was obtained in 50 mg/l silver nitrate which was not significantly different from 25 mg/l while control plants produced only 50.53% green leaves. Furthermore, silver nitrate’s concentration up to 75 mg/l resulted in the production of longer shoots. Different concentrations of glutamic acid were not effective in controlling leaf chlorosis of in vitro roses.

Keywords