ISSN:
1573-5036
Keywords:
Rumex
;
flood tolerance
;
growth rate
;
iron toxicity
;
oxygen
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract In both hydroculture experiments and a greenhouse trial the combined effects of flooding and high iron levels on the growth and occurrence of iron toxicity were investigated in threeRumex species having different flood tolerance. In a hydroculture experiment the plants were subjected to different FeCl2 concentrations and anaerobiosis. At solution iron concentrations exceeding 750 μM, the growth rate of the flood-intolerantR. thyrsiflorus was sharply decreased. The root system was most negatively affected. Differences between the investigated species could be most likely explained from differences in root porosity and are thus closely related to a differential internal oxygen supply to the root systems. In a greenhouse experiment soil flooding was combined with the addition of different ferrous iron concentrations to the soil solution. Flooding in combination with the addition of 5 mM ferrous iron did not result in a significant decrease in biomass production of any of the investigatedRumex species, in spite of the fact that several types of shoot iron toxicity were perceived. Especially at high iron levels significant amounts of ‘bronzing’ spots on the leaves of all species were observed. Petiole iron toxicity symptoms, which result in a sagging of the petioles, was most clearly observed in the flood-intolerantR. thyrsiflorus. Although the hydroculture experiments revealed a severe effect of anaerobiosis and high iron levels on the root development and plant growth rate of especially the flood-intolerantR. thyrsiflorus, no such adverse effects were registered in the greenhouse experiments in neither of the species. This is most probably due to the fact that under greenhouse conditions theRumex species are able to locally immobilize iron by oxidation, thereby avoiding the actual iron stress. Since biomass production was hardly affected under greenhouse conditions, it is concluded that high iron levels in the soil solution are of minor importance in the different flood tolerance of theRumex species. It also indicates that great care has to be taken in the interpretation of hydroculture experiments to the actual effect of the suggested stress conditions under greenhouse or natural conditions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02150046
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