Effect of tryptophan and glutamic acid on morphological traits of Iranian and Afghan saffron

Abstract

In order to investigate the effect of amino acids tryptophan and glutamic acid on the morphological traits of the saffron medicinal plant, a factorial experiment was conducted in the form of a randomized complete block design in three replications in 2018 in the research farm of Zanjan University. The experimental treatments include three genotypes (Iranian, Afghani 1, and Afghani 2) as the main treatment and tryptophan amino acid at two levels (1 and 2 mM) and glutamic acid at two levels (1 and 2 mM) as secondary treatments. They were considered as testify. The results showed that tryptophan and glutamic acid treatments had a significant effect (p ≤ 0.01) on most of the studied traits including the number of flowers, dry weight of flowers, and vegetative body. The highest content of the number of flowers and dry weight of flowers were observed, respectively, 34.6 and 37.36 mg of dry weight. Also, the performance characteristics of the fresh weight of the flower and the dry weight of the stigma showed a significant difference (p ≤ 0.05) under the treatment of two amino acids. In total, different levels of tryptophan and glutamic acid can have an effective role in improving the morphological traits and production of this product. The use of 1 mM glutamic acid to produce the maximum vegetative body of the plant, the treatment of 1 and 2 mM of both amino acids to improve morphological indicators, and 1 mM of glutamic acid for the performance of secondary metabolites is desirable and recommended for the purpose.