Enhancing Quinoa (Chenopodium quinoa) Growth and Yield Through Seed Pretreatment and Foliar Application of Serine and Glutamine

Document Type : Research Article

Authors

R Rbei

M Baradaran Firouzabadi

M Heidari

Department of Agronomy, Faculty of Agriculture, Shahrood University of Technology, Shahrood, Iran

10.22067/jcesc.2026.95496.1425

Abstract

Introduction
One way to increase seed yield of plants is to use amino acids as biostimulants and growth regulators. Amino acids are the main components of proteins. About 20 types of important amino acids are involved in the synthesis of proteins in the cell. Amino acids play essential roles in plant metabolism, growth, and development. Among them, glutamine is particularly important because it serves as a key intermediate linking carbon and nitrogen metabolism. It also functions as a major nitrogen donor and precursor for the biosynthesis of several amino acids and other nitrogen-containing compounds, thereby contributing to numerous physiological and metabolic processes in plants. Another amino acid that can lead to improved performance in plants under stress and non-stress conditions is serine. The amino acid serine is essential for some cellular processes, including protein synthesis and some amino acids such as glycine, cysteine and methionine in plants. In order to investigate the effect of amino acids on improving quinoa (Chenopodium quinoa) grain yield, an experiment was conducted in 2013 in the laboratory and research farm of the Faculty of Agriculture, Shahrood University of Technology.

Materials and Methods
The experiment was conducted as a factorial arrangement in a randomized complete block design with three replications. The treatments consisted of two factors: seed pretreatment and foliar application. Seed pretreatment was applied at four levels: no pretreatment, distilled water, serine, and glutamine, with serine and glutamine applied at a concentration of 200 mg L⁻¹. Foliar application was also performed at four levels: distilled water (control), serine, glutamine, and a combination of serine and glutamine, each applied at a concentration of 200 mg L⁻¹. Pretreatment of seeds with the above-mentioned substances and concentrations was carried out for three hours, observing the principles of seed aeration. After that, the seeds were dried in the shade and used to continue the experiment and measure the traits. Foliar application with the desired concentrations was carried out before flowering of the plant under suitable conditions so that the leaves were completely wet. Two weeks after foliar application, the measurement of the traits began.

Results and Discussion
The results showed that foliar application of glutamine alone and combined application of serine and glutamine resulted in a significant increase of 7.41 and 8.58 percent in relative leaf water content compared to the control, respectively. Four treatment combinations, pretreatment and application with serine, pretreatment and application with glutamine, pretreatment with serine application with serine and glutamine, pretreatment with glutamine and application with these two substances increased the weight of 1000 grains in the range of 10.27 to 12.20 percent and increased the number of grains in the panicle in the range of 9.10 to 11.97 percent. Combined foliar application of serine and glutamine as well as application of glutamine and serine alone resulted in an increase of 0.82, 0.59, and 0.52 percent in grain protein, respectively. The highest seed yield was obtained with the application of pretreatment and foliar application of serine, pretreatment and foliar application of glutamine and pretreatment with glutamine along with combined foliar application of serine and glutamine, which showed an increase of 30.52, 30.91, and 31.02 percent compared to the control, respectively.

Conclusion
Finally, within the scope of the research conducted, the use of pretreatment of seeds with serine and glutamine along with foliar application of these two substances is recommended to increase protein and seed yield of quinoa. When each of these two amino acids was used as a pretreatment and foliar application, they showed a greater effect on the aforementioned traits. Among the four foliar application treatments, the combined application of serine and glutamine performed better. Finally, within the scope of this study, the use of the two amino acids serine and glutamine (200 mg L^-1) as foliar application is recommended to improve protein content and quinoa seed yield.

Keywords

Grain protein

Lipid peroxidation

1000-seed weight

Subjects

• Environmental stresses

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Authors retain the copyright. This is an open access article distributed under Creative Commons Attribution 4.0 International License (CC BY 4.0)

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