Influence of lead application to roots and shoots of 'Elsanta' strawberry plants on growth, gas exchange and lead partitioning

摘要

The influence of Pb application on growth, gas exchange and Pb concentrations in Elsanta strawberry plants was investigated in 2 experiments. In the first trial, Pb was supplied with the nutrient solution as sulfate or as acetate in a concentrationof 200 mg/litre. The pH of the nutrient solution was fixed at either pH 5 or pH 7. Vegetative growth was scarcely influenced with a slight reduction of DM production in lead sulfate-treated plants. Acidified nutrient solution (pH 5) resulted in a significant increase in growth in contrast to plants which received a pH 7 nutrient solution. Similar to the growth pattern, photosynthesis rate was slightly reduced only in the lead sulfate variant. Transpiration rate was not affected by the treatments. Pb application resulted in markedly increased Pb concentrations in all parts of the strawberry plants. The highest Pb accumulation was found in the roots, whereas Pb concentration in fruits was significantly lower. In experiment 2, foliar Pb application did not influence growth and gas exchange of the strawberry plants. However, spraying lead acetate resulted in a marked increase in the Pb concentration in fruits and leaves. Pb content in the fruits exceeded the critical level for human nutrition. In contrastto lead acetate, lead sulfate did not alter the Pb content in any part of the strawberry plants.