Effects of supplemental ultraviolet-B and cadmium on growth, antioxidants and yield of Pisum sativum L.

The impact of supplemental UV-B irradiation (sUV-B) and cadmium (Cd, 68 micromol kg(-1) soil) singly and in combination was studied on growth, pigments, enzymatic and non-enzymatic antioxidants, lipid peroxidation (LPO), uptake and translocation of Cd and yield of pea plants under field condition. Compared to the control, both the stresses individually and in combination led to in reductions in growth, photosynthetic pigments, ascorbic acid, catalase (CAT) activity and yield, whereas a reverse trend was observed for flavonoids, thiols and proline contents, superoxide dismutase (SOD) and peroxidase (POD) activities, and LPO. The uptake and translocation of Cd increased in different plant parts with duration of its treatment and also when applied with sUV-B. Combined treatment of sUV-B and Cd inhibited the growth and various metabolic processes antagonistically except the CAT activity which showed additive response. Further, CAT activity may be used as a bioindicator parameter to evaluate the individual and interactive effects of both the stresses.