caa a22 4500 477110371 CHVBK 20180405111607.0 cr unu---uuuuu 170330e19960101xx s 000 0 eng 10.1007/BF00011166 doi (NATIONALLICENCE)springer-10.1007/BF00011166 Phytotoxic effects of the high molecular weight fraction of an aqueous leaf litter extract on barley root development [Elektronische Daten] [I. Brunner, J. Luster, M. Ochs, P. Blaser] The root development of barley seedlings grown for one week in an aerated nutrient solution was studied in the presence of dissolved organic matter from an aqueous chestnut leaf litter extract. In particular, the different effects of low and high molecular weight fractions (small molecules: molecular weight <1000; large molecules: >10,000) of the leaf litter extract were examined. In the presence of large molecules root growth was inhibited, an irregular root tip morphology was observed, and Ca and Mg concentrations in the shoots were lower than in control plants. These phytotoxic effects were not caused by the formation of an impermeable layer of large molecules on the root surfaces that lower accessibility for nutrient cations as inferred from voltammetric experiments. A germination assay using spruce seeds, however, indicated allelochemical effects of large molecules, which exhibit a higher aromaticity than the small molecules as indicated by spectroscopic characterisation. In the growth experiments with small molecules, no influence on the root development of barley was evident, but an increase of Ca and Mg in the shoots was detected. During these growth experiments, a large amount of the small molecules, mainly simple phenols and amino acids, disappeared from the nutrient solution. The loss of small molecules was most likely the effect of mineralisation. Kluwer Academic Publishers, 1996 adsorption behaviour nationallicence dissolved organic matter nationallicence leaf litter extract nationallicence molecular weight fractions nationallicence phytotoxicity nationallicence root development nationallicence DOC : dissolved organic carbon nationallicence DOM : dissolved organic matter nationallicence LLE : leaf litter extract nationallicence MW : molecular weight nationallicence HMDE : hanging mercury drop electrode nationallicence Brunner I. Snow and Landscape Research (WSL), Swiss Federal Institute for Forest, CH-8903, Birmensdorf, Switzerland aut Luster J. Snow and Landscape Research (WSL), Swiss Federal Institute for Forest, CH-8903, Birmensdorf, Switzerland aut Ochs M. Swiss Federal Institute for Environmental Science and Technology (EAWAG), CH-8600, Dübendorf, Switzerland aut Blaser P. Snow and Landscape Research (WSL), Swiss Federal Institute for Forest, CH-8903, Birmensdorf, Switzerland aut Plant and Soil Kluwer Academic Publishers; gopher://gopher.wkap.nl 178/1(1996-01-01), 83-93 0032-079X 178:1<83 1996 178 11104 https://doi.org/10.1007/BF00011166 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00011166 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Brunner I. Snow and Landscape Research (WSL), Swiss Federal Institute for Forest, CH-8903, Birmensdorf, Switzerland aut NATIONALLICENCE 700 1- Luster J. Snow and Landscape Research (WSL), Swiss Federal Institute for Forest, CH-8903, Birmensdorf, Switzerland aut NATIONALLICENCE 700 1- Ochs M. Swiss Federal Institute for Environmental Science and Technology (EAWAG), CH-8600, Dübendorf, Switzerland aut NATIONALLICENCE 700 1- Blaser P. Snow and Landscape Research (WSL), Swiss Federal Institute for Forest, CH-8903, Birmensdorf, Switzerland aut NATIONALLICENCE 773 0- Plant and Soil Kluwer Academic Publishers; gopher://gopher.wkap.nl/ 178/1(1996-01-01), 83-93 0032-079X 178:1<83 1996 178 11104 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer