influence of kno3, cacl2 and mgso4 concentrations on growth and cichoric acid accumulation in hairy root culture of purple coneflower (echinacea purpurea l.)

background: purple coneflower (echinacea purpurea l.) is one of the most important medicinal plants. hairy root culture of echinace, represent a valuable alternative to field cultivation for the production of bioactive secondary metabolites. objective: the present study investigates the effects of kno3, cacl2 and mgso4 concentrations on growth and the biosynthesis of cichoric acid in echinacea purpurea hairy root culture. methods: agrobacterium rhizogenes strain r15834 was used for hairy root induction. the experiment was performed with 0.5 g of fresh hairy roots (about 2 cm long segments) per 100 ml erlenmeyer flasks containing 30 ml of hormone-free liquid 1/2ms salts with b5 vitamins supplemented with different amounts of kno3 (3131, 3939, and 4747 mg/l), cacl2 (85, 170, and 340 mg/l) and mgso4 (370 (control), 600, and 1600 mg/l). after 4 weeks, growth parameters and cichoric acid amounts were assessed. results: results indicated that the highest fresh (99.69 g/l) and dry weight (6.91 g/l) of hairy roots were achieved using 3131 mg/l kno3. fresh and dry weights of hairy roots in various cacl2 and mgso4 concentrations were not significantly different from those of control. the highest amount of cichoric acid (30.55 mg/g dw) was produced by 1600 mg/l mgso4 treated hairy roots after 4 weeks. conclusion: the present work demonstrated the effectiveness of modified 1/2ms salts supplemented with b5 vitamins medium for improving hairy root growth and in vitro production of cichoric acid.