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Functional Plant Biology Functional Plant Biology Society
Plant function and evolutionary biology
RESEARCH ARTICLE

Effect of Temperature on Total Nitrogen Distribution in Pennisetum Americanum

TN Theodorides and CJ Pearson

Australian Journal of Plant Physiology 8(2) 201 - 210
Published: 1981

Abstract

Total N uptake and distribution and relative accumulation of N and dry matter were studied from 26 days after sowing until 50% anthesis in two genotypes of Pennisetum americanum growing at day/night temperatures ranging from 18/13 to 30/25°C. Nitrogen was taken up throughout growth and there was no indication of a net loss of N from the whole plant or from individual organs. Rate of N uptake was closely correlated with dry weight increments until stem elongation: there was a single relationship between uptake and dry weight increment over the three temperatures and two genotypes (41 mg N per g whole-plant dry weight increment). Relative rates of N accumulation and dry weight increment were higher at high temperature and again a single equation related relative accumulation of N to dry weight over all treatments. However, in contrast to the constancy of N uptake per unit dry weight, N distribution within the plant was affected by temperature. Low temperatures resulted in high root N concentrations and relatively high NO3 concentrations in root and stem apices. Temperature did not affect the proportional distribution of N between organs of the top.

The results are interpreted as showing that activity of components of the nitrogen pathway are adjusted to maintain a constant rate of N uptake per unit dry weight increment in vegetative growth, but that N distribution within pearl millet is sensitive to temperature.

https://doi.org/10.1071/PP9810201

© CSIRO 1981

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