Springer Online Journal Archives 1860-2000
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Abstract Three clones of spruce (Picea abies Karst.) were grown in sand culture for 9 weeks, whereafter they were transferred to water culture for 3 days. The plants were supplied with or grown in nutrient solution containing 0, 0.1, 1.0 respectively 10 mM AlCl3. The monomer Al fraction (including Al3+) and the Al3+ fraction were determined in the fresh nutrient solutions. The shoot/root dry weight ratio and the water content in shoots and roots were determined, and the main cationic composition (Al, K, Ca, Mg, Mn) in needles, stems and roots were analysed. A short term uptake experiment was performed 3 days after the plants were transferred from sand culture to water culture. The K+(86Rb+) and Ca2+(45Ca2+) uptake rates in the roots were determined in absence of external AlCl3. A high proportion of the supplied Al was taken up by the plants; 57% of total supply in the 0.1 mM Al treatment and 20% in the 1.0 mM Al treatment. Between 11% and 28% of the total Al taken up in the 0.1–10 mM Al treatments was exported to the shoot, indicating that Al not only was bound in the root free space, but also crossed the plasmalemma. Al decreased the Ca and Mg concentrations in the roots. The short term uptake experiment also showed that Ca2+(45Ca2+) uptake in the roots decreased with increasing external Al concentration. However, Ca and Mg concentrations were not lower in the shoots, except at the 10 mM Al treatment. This indicates that a higher percentage of the ions taken up was exported to the shoots in presence of Al. Concentrations of Mn and K in the roots were about the same in the Al treatments as for the control, except that the K concentration decreased at the 10 mM Al treatment. K levels in stems and needles increased with increasing Al treatment probably as a result of a decreased efflux from the roots combined with a higher export/uptake ratio. However, at the end of the cultivation period, K+(86Rb+) uptake, in the roots, decreased with increasing Al treatment, probably mainly due to a reduced ATP level. The shoot/root dry weight ratio was highest for the two highest Al treatments (1.0 and 10 mM) due to a reduced root growth.
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