Effects of Copper on Gas Exchange of Amaranthus Stomata
ZHU Jian et al (School of Life Sciences,Taizhou University,Linhai,Zhejiang 317000)
[Objective] The purpose of the study was to explore the influence of copper stress on the physiological process of Amaranthus.[Method] The influences of copper on the stomatal gas exchange and photosynthetic pigments of Amaranthus seedlings and the copper distribution in plants were studied by soil culture.[Result] The treatment with 0.5 mmol/kg copper was favorable for Amaranthus growth.The net photosynthetic rate of Amaranthus reduced obviously along with copper concentration increasing,which was mainly attributed to nonstomatal limitations.Transpiration rate,light saturation point,apparent quantum efficiency and photosynthetic pigments contents decreased, while light compensation point increased.Dark respiration rate increased under the copper concentration of 0.5～2.0 mmol/kg and decreased under the copper concentration of 4.0 mmol/kg.There was far higher copper concentration in roots of Amaranthus than that in leaves.The copper concentration in roots and leaves obviously increased along with the increment of copper concentration in treatments.[Conclusion] The research provided the basis for Amaranthus planting and discussing the physiological mechanism of copper poison to plant.