Hormonal Priming with BAP and GA3 Induces Improving Yield and Quality of Saffron Flower Through Promotion of Carbohydrate Accumulation in Corm

Abstract

This work investigated the effects of the hormonal priming of saffron corms before planting with 6-benzylaminopurine (BAP) as cytokinin, and gibberellic acid (GA3) on saffron quantity and quality by examining the number of flower, fresh and dry weight of flower, fresh and dry weight of stigma, length of stigma, crocin, picrocrocin and safranal compounds in stigma, anthocyanin content of petals as well as the changes in total soluble carbohydrate in corm and leaf during flowering. The results indicated that hormonal priming by using application of BAP improved yield of saffron flowers by increasing the number of flowers, fresh and dry weight of each flower, and stigma by. In addition, length of stigma improved by application of GA3 compared with BAP and untreated plants. The applied BAP and GA3 led to an increase of total soluble sugar in leaf and corm of saffron, and they had a significant difference with non-hormonal priming treatment. In addition, the total soluble sugar concentration in corm of saffron was more than that in leaves under hormonal priming. The anthocyanin content of petals of saffron had an increase under BAP application compared with GA3, whereas the application of GA3 had a significant difference with control and improved the anthocyanin of flower petals, but its effect was less than application of BAP. Interestingly, this study showed that BAP led to a much higher increase in the concentration of crocin, picrocrocin, and safranal compounds in stigma, as compared to the GA3 and control treatment. Furthermore, this experiment suggests that total soluble carbohydrates of the corm may play an important role during flowering on saffron quality because there were clearly higher concentrations of crocin, picrocrocin, and safranal compounds in stigma and anthocyanin content of petals under BAP and GA3 application. Finally, this work indicated that an increase in the saffron yield and quality of flowers is associated with an increase in the contents of carbohydrates in corm caused by the application of BAP.