EFFECT OF IRRADIATION ON INTERNAL STRUCTURE AND ACTIVE INGREDIENT OF ECHINACEA PURPUREA

Abstract

Series of experiments were carried out successively during the years of 2013 to 2015. The effects of UV-C, UV-B and gamma radiation on the anatomical structure of Echinacea seedling and biochemical components of callus and cell suspension were investigated. The results indicated that incubation periods and UV-C treatments were effective on growth parameters and chemical components. It is obvious that growth parameters & guaiacol peroxidase (G-POD) activity in callus and cell suspension cultures in addition to caffeic acid derivatives & phenylalanine ammonia lyase (PAL) in cell suspension and non-enzymatic antioxidant activity in callus culture increased by increasing incubation period and the reverse was true for caffeic acid in callus. On the other hand, incubation period 48 hours was the most influence in total phenols content and PAL activity of callus while,incubation period 72 hours achieved the highest increment in total phenols content and antioxidant activity in cell suspension culture. All UV-C treatments led to an increment in caffeic acid & antioxidant activity of callus cells and growth parameters, total phenols content & antioxidant activity of cell suspension and the reverse was true for G-POD activity in callus and cell suspension cultures comparing to the control. On the other side, the two exposure times 30 & 60 min led to increasing callus growth and total phenols while exposure time 60 min detected an increment in caffeic acid of cell suspension and PAL activity in the two types of cultures as compared to the control. UV-B led to an increment of all growth parameters and antioxidant activity in callus and cell suspension and caffeic acid derivatives in cell suspension by increasing incubation period and the reverse was true for G-POD activity incell suspension and PAL activity in both types of cultures. While, incubation period 2 weeks was more effective in caffeic acid, total phenols and G-POD activity incallus cells and incubation period one week only fortotal phenols in cell suspension. Apart from the effect of second exposure time (4 hours) on fresh weight and growth index of cell suspension, UV-B led to an increment of all growth parameters in the two types of cultures and G-POD activity in callus cells and reverse was true for G-POD activity incell suspension & PAL activity in callus cells comparing to the control. On the other side, the two exposure times 2 & 4 hours increased antioxidant activity in the two types of cultures. Meanwhile, exposure time 2 hours led to increase caffeic acid and total phenols in callus cells, while, the maximum increase in caffeic acid, total phenols and PAL activity in cell suspension was achieved by 4 hours exposure time. Likewise, using 2 UV-B lamps for 2 hours was the most effective in creating more biochemical components.