Study of Effect of Silicon on Some Anatomical and Physiological Characteristics of Borage (Borago officinalis L.) in Hydroponic Conditions

Study of different factors affecting on improvement of growth and development of medicinal plants is very important. Inorganic elements are considered as those affecting factors. The aim of this research was to study the effects of different silicon concentrations on anatomical and developmental characteristics and some growth parameters of borage (Borago officinalis L.) in hydroponic conditions. The effects of different concentrations of silicon on anatomical features of epidermis and stomata cells and some growth parameters including quantity of photosynthetic pigments and proline in borage were studied. To this end، a hydroponics experiment was conducted randomly with different amounts of silicon including 0، 0. 5، 1، 1. 5، 2، 2. 5 mM in four replications in greenhouse conditions. The results showed that 1. 5 mM silicon resulted in a significant increase in stomata length and width، and stomatal index in borage leaf comparing with control and other treatments. Also application of 1. 5 mM silicon showed positive effects on fresh weight of shoot and total chlorophyll content of plants compared with control. However it seems that silicon in high concentrations had negative effect on growth and anatomical attributes of the plant. According to study of physiological and anatomical results، positive effects of silicon on pharmaceutical borage are just observed in appropriate and endurable concentrations for the plant.