Premium
Growth and nitrate uptake properties of plants grown at different relative rates of nitrogen supply. I. Growth of Pisum and Lemna in relation to nitrogen
Author(s) -
OSCARSON P.,
INGEMARSSON B.,
LARSSON C.M.
Publication year - 1989
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.1989.tb01639.x
Subject(s) - pisum , relative growth rate , sativum , lemna , nitrogen , lemna gibba , botany , biology , nitrate , lemna minor , biomass (ecology) , shoot , growth rate , horticulture , zoology , agronomy , chemistry , aquatic plant , ecology , macrophyte , mathematics , geometry , organic chemistry
The relations between growth and internal nitrogen concentrations were investigated in nonnodulated Pisum sativum L. cv. Marma and Lemna gibba L. grown at relative rates of nitrate‐N additions (R A ) varying from 0.03 to 0.27 d 1 ( Pisum ) and 0.05 to 0.40 d 1 ( Lemna ). At R A ≤0.21 d 1 ( Pisum ) and ≤0.30 d 1 ( Lemna ), the relative growth rate (RGR) correlated well with R A whereas higher R A was not met by any further increawse in growth rate. The tissue nitrogen concentrations at growth‐limiting R A increased linearly with RGR. The slope of these lines indicate a maximum nitrogen productivity (amount of biomass formed per unit nitrogen and time) of 14.4 g DW g 1 Nd 1 for Pisum and 15.9 g DW g 1 N d 1 for Lemna. Extrapolation of the plots to RGR=0 yielded intercepts of 10–15 mg N g −1 DW for Pisum tissue, whereas for Lemna the intercepts were closer to the origin than for Pisum. These intercepts formally define a fraction of the total plant nitrogen that appears not to be active in production of new biomass, her termed ‘non‐growth nitrogen’. The partitioning of nitrogen as well as biomass to the roots increased at low R A , and is discussed in relation to activity of shoots and roots, respectively.