Effects of N-application on utilization of ¹⁵N and ¹³C and quality in two wheat cultivars

Abstract

We studied N uptake and distribution in wheat, and the incorporation of nitrogen and carbon into gluten and non-gluten proteins using a double-labelling approach with ¹⁵N and ¹³C. Doses of N-fertilizer were split and applied at emergence, onset of stem elongation, and heading at rates of 280/140/140 mg N pot⁻¹, respectively simulating 90/45/45 kg N ha⁻¹. Five different combinations of N-fertilizations containing no or 10 % ¹⁵N were performed. The recovery of ¹⁵N added at the stages emergence, stem elongation or heading were 42, 60, and 64 %. Application of ¹⁵N at all three stages yielded in 51 % recovery. Remobilisation of straw N was greater for Golia. The ¹⁵N concentration in gluten proteins of Golia show higher values than Gönen. The ratio of ¹⁵N gluten/¹⁵N non-gluten proteins of Golia were higher, which implies a lower non-gluten protein activity during grain filling. The ¹³C concentration in gluten and non-gluten proteins did not differ between both cultivars.

Keywords:

• carbon-13
• gluten-proteins
• nitrogen-15
• N-fertilizer
• N-uptake
• N-utilization; non-gluten proteins
• wheat

Acknowledgements

[Acknowledgement] The technical support and analysis provided by Mrs. Susanne Moryson is gratefully acknowledged.