Effects of silica treatment on some morphological, anatomical and physiological characteristics of Iranian borage (Echium amoenum Fisch & C.A. Mey)

In medicinal plants، secondary metabolites are very important and factors influencing their quantity and quality are considered. Iranian borage (Echium amoenum Fisch. & C. A. Mey.) belonging to Boraginaceae family is a long-day، biennial، herbaceous plant، with a lot of rough trichomes، is found in northern Iran. In the present work، effects of silicon on some morphological، anatomical and physiological characteristics of this plant were investigated. For this purpose، borage plants، cultivated in hydroponic system in greenhouse، were treated with silicon (as sodium silicate) at 3 concentration levels (0، 0. 2 and 0. 7 mM). The experiment was carried out as completely randomized design. Some morphological and anatomical characteristics such as length of trichomes، number of trichomes، number of stomatal cells، cuticle thickness، stomatal index and palisade parenchyma cells density of treated plants and control were measured and anthocyanin and flavonoids content was also evaluated. Based on the results، in silicon-treated plants، compared to control، the stomatal index was decreased. The cuticle thickness، palisade parenchyma cells density، trichomes length، and anthocyanin and flavonoids content in silicon-treated plants were increased significantly. But، there was no significant difference in number of trichomes in the treated plants.