The Effect of 24-Epibrassinolide Treatments at Different Concentrations on Some Growth Parameters and Crocin Level in Saffron (Crocus sativus L.)

Abstract

Brassinosteroids (BRs) are steroid phyotohormones that play roles in plant growth, secondary metabolite accumulation, stress response, and adaptation. Saffron (Crocus sativus L.) is an important plant with significant pharmacological effects due to its rich phytochemical content. Crocin, the main pigment of the saffron stigma, is a natural food colorant and has anti-cancer activity. In this study, the effects of 24-Epibrassinolide (EBL) at different concentrations (10-6 , 10-7 , 10-8 and 10-9 M) on corm (mother corm) and aerial part related parameters as well as the level of crocin in saffron were investigated. The experiment was conducted in a plant growth cabinet as randomized plots design with 3 replications. 24-Epibrassinolide treatments did not affect the rates of shoot emergence from saffron corms, while 10-8 and 10-9 M EBL treatments increased the number of active nodium and cormlet (daughter corm) as compared to control. All the applied EBL concentrations significantly increased the root and shoot lengths of saffron plants. The maximum number of flowers per plant was observed as a result of the 10-8 M EBL treatment. Exogenous treatment of 10-9 M EBL enhanced the crocin level by 96.0% compared to the control. This is the first study to evaluate the effects of BRs in saffron.