Effects of salinity on Na, K and Ca contents of borage (Borago officinalis L.) and echium (Echium amoenum Fisch. & Mey.)

Soil salinity affects ion concentrations of plant tissues and this may alter the quality of medicinal plants. Experiments were conducted during 2003 at the Isfahan University of Technology Campus, Isfahan, Iran, to assess the effects of five soil salinity levels (3.2, 3.6, 4.5, 5.4 and 7.5 dS m-1) on Na, K, and Ca contents of borage and echium. Each plant species was studied in a separate experiment using a completely randomized design with three replications. The increase in soil salinity increased Na, but decreased K and Ca contents and K/Na ratio of aerial parts of both borage and echium plants. Borage had much higher Na concentration and much lower K/Na ratio than echium. Consequently, it could be implied that the medicinal quality of borage might be more adversely affected by soil salinity than that of echium. Soil salinity should be considered as an important factor in borage production as a medicinal plant.