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Global climatic changes: modelling the potential responses of agro-ecosystems with special reference to crop protection.
1995
Goudriaan J. | Zadoks J.C.
The effects of zinc on cell viability and on mitochondrial structure in contrasting cultivars of Festuca rubra L. - a rapid test for zinc tolerance
1995
Davies, K.L. | Davies, M.S. | Francis, D. (School of Pure and Applied Biology, University of Wales, College of Cardiff, PO Box 915, Cardiff CF1 3TL (United Kingdom))
Vegetative growth of soybean as affected by elevated carbon dioxide and ozone
1995
Reinert, R.A. | Ho, M.C. (USDA-ARS, Department of Plant Pathology, North Carolina State University, Raleigh, North Carolina 27695 (USA))
Effect of nitrogen in forests on root production, root system and mycorrhizal state
1995
Kottke, I. (Tubingen Eberhard-Karls-Univ. (Germany). Botanisches Inst.)
Norway spruce: cytogenetic studies using different dividing tissues and methods
1995
Guttenberger, H. | Kohler, B. | Muller, M. (Graz Univ. (Austria). Plant physiology Inst.) | Borzan, Z. (Zagreb Univ. (Croatia). Forestry Fac.)
The haploid chromosome set of Norway spruce consists of 12 chromosomes. Most of the chromosomes are very similar in their morphology (length, arm ratio, secondary constriction). For the CGBI it is necessery to recognize all chromosomes. Therefore we used different banding methods to solve this problem. We used the root meristem and the dividing cells of the macrogametophyte as test objects. We discussed morphology of chromosomes of these two different dividing tissues. The use of image analysis equipment made it possible to get in a relatively short time a great number of data for statistical analysis. Another method was, to use an expert-system for data analysis. Finally 3-D models of interphase nuclei were reconstructed.
Mostrar más [+] Menos [-]Secondary metabolites in mycorrhizal and non-mycorrhizal roots of conifers
1995
Weiss, M. | Mikolajewski, S. | Peipp, H. | Strack, D. (Pflanzenbiochemie Inst., Saale (Germany)) | Heller, W. | Steiner, K. | Sandermann, H. (Biochem. Pflanzenpath. Inst., Neuherberg (Germany)) | Wray, V. (Biotechnologische Forschung mbH Ges., Braunschweig (Germany))
Tissue specific localization of soluble secondary metabolites was demonstrated in ectomycorrhizae and uninfected roots of Picea abies, Larix decidua, Pinus sylvestris and Abies alba. Compounds were analysed by HPLC and by histochemical methods. Specific distribution and age-dependent changes were observed with several metabolites. For catechin corresponding patterns were found within the cortex of all investigated conifers. Levels of this metabolite were highest within the apical cortex cells and decreased on aging of the tissue. In spruce contents of catechin showed evident seasonal changes. Stilbene glucosides were detected within the pericycle of spruce roots and as well the phloem tissue of larch with levels increasing during root development. In larch two anthocyanins accumulated in the calyptra. In older tissues of larch roots larixin-glucosid and quercetin-rhamnosid were detected, the latter with highest levels in the phloem tissue. For cell wall bound ferulic acid increasing levels could be found concomitant with the development of the root.
Mostrar más [+] Menos [-]Influence of different depositions of air pollution on fine roots and mycorrhizae of scots pine
1995
Munzenberger, B. | Lehfeldt, J. (Forest Ecology Inst., Eberswalde (Germany)) | Huttl, R.F. (Cottubs Brandenburg Technical Univ. (Germany). Chair of Soils Protection and Recultivation)
Distribution patterns of ectomycorrhizal types and length density of finest roots were investigated in three comparable Scots pine ecosystems located along a deposition gradient of air pollutants in the new states of Germany. The plots Rosa, located near Bitterfeld and Halle, had received high depositions loads of SO2, NOX and alkaline fly ashes due to chemical industries and brown coal fired power plants in the former German Democratic Republic. Taura, located near Leipzig, was moderately affected by air pollutants. The background site Neuglobsow is located in a remonte area north of Berlin. All the three plots were dominated by only a few mycorrhizal types. Mycorrhizal projection area of these types was highest in Neuglobsow and strongly reduced at the polluted plots. The distribution patterns of mycorrhizal types differed also qualitatively. Length density of finest roots was lower in the humus layer of Neuglobsow than in the humus layer of Rosa and Taura. The results are correlated to high nutrient inputs and high rates of N-mineralization at the impacted plots.
Mostrar más [+] Menos [-]Mechanisms of heavy metal detoxification in ectomycorrhizas
1995
Turnau, K. (Jagiellonian Univ., Krakow (Poland). Botany Inst.)
The paper summarizes the main results of reach on heavy metal detoxification in ectomycorrhizas of Rhizopogon roseolus, Paxillus involutus, Cenococcum geophilum and Pisolithus arrhizus formed on Pinus sylvestris roots collected from heavily polluted areas in Poland. The data were obtained by methods including electron microscopy (TEM, SEM) accompanied by EELS and EDAX, cytochemical stainings and capillary electrophoresis. All of the species described in the paper are fungi highly resistant to toxic elements. As detoxification in mycorrhizas is dependent on both partners, the phenomenon was studied in fungi and in Pinus sylvestris roots. The strongest element-filtering effect was observed in R. roseolus / P. sylvestris symbiosis. This mycorrhiza type was characterized by the accumulation of heavy metals in the fungal mantle, and a gradual decrease of these elements was observed along the Hartig net towards the inside of the root. Potentially toxic elements were localized intercellularly in crystals deposited on the mantle and hyphal surface and in pigmented layer of the cell wall of the extramatrical hyphae, and the hyphae of the outer mantle layer. They were also detected intracellularly within electron-opaque depositions in the vacuoles. Much lower levels of toxic elements were detected in plant cells. The most common place for heavy metal accumulation was the phenolic material of the cortical cells.
Mostrar más [+] Menos [-]Degradation and restoration processes in crowns and fine roots of polluted montane Norway spruce ecosystems
1995
Cudlin, P. | Chmelikova, E. (Academy of Sciences, Ceske Budejovice (Czech Republic))
The classification of chromosomal defects of spruce trees as an alternative in environmental studies
1995
Muller, M. | Grill, D. (Graz Univ. (Austria). Plant Physiology Inst.)
A plant test system by the classification of chromosome aberration in the root tip meristems of young spruce plants (Picea abies (L.) Karst.) has been used to study the environmental influence on the genetic material of trees at natural sites and under defined conditions of greenhouses and open-top chambers. All our results suggest that this plant test system is a valuable tool in environmental monitoring.
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