¹⁵N allocation into wheat grains (Triticum aestivum L.) influenced by sowing rate and water supply at flowering under a Mediterranean climate

ABSTRACT

This study examined the effects of a reduced wheat sowing rate (250 vs. 500 grains m^–2) on grain yield, uptake of ¹⁵N into grains, and the incorporation into gluten and non-gluten proteins of wheat under field conditions in the Aegean region. A single ¹⁵N application was applied at stem elongation, at flowering, or at both developmental stages. Each ¹⁵N treatment included either additional water supply, or no additional water supply at flowering. Sowing rate (either 250 or 500 grains m^–2) had no impact on grain yield. Grain yield increased with additional water supply, but at the expense of protein quality, because of a decrease in the protein content of gluten. The ¹⁵N content of the gluten and non-gluten proteins at grain maturity was not different among cultivars. ¹⁵N applied at both stem elongation and flowering was found in comparable amounts in grains and protein fractions, irrespective of sowing rate.

KEYWORDS:

• Gluten
• grain yield
• irrigation
• isotope biology
• isotope ecology
• nitrogen-15
• sowing rate
• proteins
• Turkey
• wheat

Acknowledgements

We are very thankful to Mrs Susanne Moryson for technical assistance. We are very grateful to the anonymous reviewers, and also to Prof. Dr. R.B. Patterson, and Mrs Amber L. Beseli, Department of Crop Science, North Carolina State University, who gave us some very valuable hints and suggestions which have improved the paper. The field experiment was done at the Department of Crop Science, Faculty of Agriculture, Adnan Menderes University, Aydin, Turkey.

Disclosure statement

No potential conflict of interest was reported by the authors.