INFLUENCE OF CADMIUM AND NICKEL ON PHOTOSYNTHESIS AND WATER RELATIONSIN WHEAT LEAVES OF DIFFERENT INSERTION LEVEL

Cd2+ and Ni2+ differendy affected the rates of net photosynthesis (P(N )) and transpiration (E), chlorophyll (Chl) content, and stomatal cond uctance (g(s) in different leaves of wheat. P(N) and Chl content in th e top leaf were affected more than the lower leaves by Ni2+, whereas t he deleterious effect of Cd2+ was more pronounced in the third leaf. N i2+ and Cd2+ slightly decreased.the relative water content and leaf wa ter potential of all the leaves after 2 d of treatment. However, this reduction was relatively more severe under Cd2+ treatment than with Ni 2+ particularly in the top leaf after 4 d of the treatment.