Photosynthetic activity in relation to chlorophylls, carbohydrates, phenolics and growth of a hybrid Salix purpurea 3 triandra 3 viminalis 2 at various Zn concentrations

The aim of the present study was to determine the effect of various Zn application levels on some physiological, morphological and biochemical parameters of a hybrid Salix purpurea 9 triandra 9 viminalis 2. Plants were cultivated under control conditions with application of Zn in the range 0–5 mM. The effects on net photosynthesis rate (PN), stomatal conductance (gs), transpiration rate (E), intercellular CO2 (Ci), chlorophyll a and b, carotenoids, growth, sugars and phenols were analysed. Our investigations confirmed a dual role of Zn, with benefits at the level 1–2.5 mM, and a decrease of measured photosynthesis activity, carbohydrates and chlorophyll below and above this range. Moreover, the decrease of these parameters at the highest Zn application did not reach the level of control plants. This means that this species may have further potential as an accumulator in polluted areas. However, phenols revealed a continuous increase together with Zn increase in the medium.