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Preferential Assimilation of Ammonium Ions from Ammonium Nitrate Solutions by Apple Seedlings
Author(s) -
FRITH G. J. T.,
NICHOLS D. G.
Publication year - 1975
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1975.tb03163.x
Subject(s) - ammonium , nitrate , nitrogen , chemistry , ammonium nitrate , nutrient , inorganic chemistry , assimilation (phonology) , botany , biology , organic chemistry , philosophy , linguistics
Apple seedlings, Pyrus malus L., were grown in complete nutrient solutions containing nitrate, ammonium, or ammonium plus nitrate as the nitrogen source. Uptake of nitrogen was calculated from depletion measurements of the nutrient solutions and by using 15 N labelled nitrate and ammonium salts. If the plants received nitrogen as ammonium only or as nitrate only, the amounts of nitrogen taken up were similar. However, if the seedlings were supplied with ammonium nitrate, the amount of nitrate‐nitrogen assimilated was only half that of ammonium. Nevertheless, if ammonium and nitrate were supplied to a plant with a split‐root system, with each root half receiving a different ion, the uptakes were similar. The possibility of independent inhibition by ammonium of both nitrate uptake and reduction in the roots is discussed.