Effect of Tryptophan and Glutamic Acid on Phytochemical Traits of Iranian and Afghan Saffron

Abstract

In order to investigate the effect of Tryptophan and Glutamic acid amino acids on physiological traits of saffron, a factorial experiment was conducted in a randomized complete block design with three replications in 2019 at the research farm of Zanjan University. Experimental treatments include three genotypes (Iranian, Afghani 1 and Afghani 2) as the main treatment and the amino acid Tryptophan at two levels (1 and 2 mM) and Glutamic acid at two levels (1 and 2 mM) as sub-treatments, were considered with witnesses. The results showed that Tryptophan and Glutamic acid treatments had a significant effect about one percent (0.01 %) on the main traits including flower number, flower dry weight, vegetative body, phenol yield, antioxidant activity and crocin. Also, yield traits of phenol, flavonoids and antioxidants treated with two amino acids showed a significant difference about five percent (0.05 %). The maximum yields of phenol and flavonoids at 2 mM Tryptophan concentration were 0.35 and 0.026 mg / g, respectively, and the lowest yields at 1 mM Glutamic treatment were 0.34 and 0.02 mg / g, per hectare. In general, different levels of Tryptophan and Glutamic acid can play an effective role in improving the physiological traits and production of this product. Application of 1 mM Glutamic acid to produce the maximum vegetative body of the plant, treatment of 1 and 2 mM both amino acids to improve physiological parameters and 1 mM Glutamic acid for the performance of secondary metabolites is desirable and recommended.