Abstract
Background
Bromeliads with water-impounding tanks uptake water and nutrients by the leaf-absorbing trichomes present on the leaf surface while the compact root system functions as for plant anchorage on other plants. However, recent studies showed a clear role of the bromeliad roots in nutrient absorption and subsequently improving plant growth.
Aims
Accordingly, the present study aimed to compare the uptake and assimilation of inorganic and organic nitrogen by roots and leaf-absorbing trichomes of silver vase bromeliad (Aechmea fasciata).
Methods
As treatments, plants were fertilized with 0, 15 or 30 mM nitrogen (N) as either urea or ammonium nitrate applied into the tank or on the substrate (roots). Dry biomass, number of leaves, macro and micronutrient contents in leaves, chlorophylls a, b, and total carotenoids were determined. In addition, gas exchange, chlorophyll fluorescence, and nitrogen efficiency indexes were analyzed.
Results
The results showed that ammonium nitrate is taken up either by leaf-absorbing trichomes and or by roots of silver vase bromeliad. Plants fertilized with ammonium nitrate had an increase in leaf nitrogen content with the increase of nitrogen concentrations on tank. However, these increases did not result in biomass accumulation or changes in the photosynthetic apparatus.
Conclusions
Our results showed that the roots of silver vase bromeliad are more efficient for inorganic nitrogen.