Influence of nutrient supply on growth, carbohydrate, and nitrogen metabolic relations in Typha angustifolia (original) (raw)

2006, Environmental and Experimental Botany

Performance of Typha angustifolia, a species common in European wetlands, was studied in connection with wetlands eutrophication. Cultivation in a sand culture was used to follow the effect of nutrient availability per se and to study, in detail, both aboveground as well as belowground organs (rhizomes and roots) of the plant in contrast to the possibilities of field study. A complex study of growth, carbohydrate, and nitrogen metabolic relationships, with respect to tissue age, was done in plants growing in nutrient solutions that differed in their levels of N and P (oligotrophic: 0.026 mM N and 0.001 mM P; eutrophic: 2.635 mM N and 0.0999 mM P; hypertrophic treatment: 9.539 mM N and 0.999 mM P). In contrast to the poor growth of Typha plants under the oligotrophic treatment, Typha coped best under the eutrophic treatment. Further increase in nutrient availability to the hypertrophic treatment did not result in additional stimulation of growth, but instead some negative reactions appeared. Changes in the growth and allocation of biomass, in favour of shoots and including rhizomes (as compared with roots) with increasing nutrient availability, were accompanied by an increase in N allocation and content of non-structural carbohydrates in these tissues. Detailed biochemical analysis revealed significant differences between tissues of different ages. These characteristics probably reflect the physiological potential of this species for their successful spreading in natural eutrophic habitats. Moreover, a decrease in the C/N ratio, decreasing proportion of starch/soluble sugars ratio, increasing proportion of hexoses/sucrose ratio (taking into account the type and tissue age of plant organs), with increasing nutrient availability, indicate high metabolic activity of the tissues at the stage of maximum growth.