The effect of vitamin B1 and IBA on rooting and cortex cells growth of adventitious root in Rosmarinus officinalis L. cuttings under hydroponic media

Rosemary (Rosmarinus officinalis L.) is of great value as an ornamental and medicinal plant. Therefore، studying the growth، morphological and anatomical parameters of rosemary cuttings in rooting stage is of utmost importance. In recent research، the separate and combined effects of Indole 3- Butyric acid (IBA) and vitamin- B1 (thiamine) on growth، rooting and anatomical structure of adventitious roots in Rosmarinus officinalis cuttings were investigated under hydroponic conditions. A factorial experiment was implemented using nine combined treatments including IBA and vitamin B1 at three levels. The treatments were applied on cuttings for two weeks under standard condition of light، temperature and humidity in hydroponic medium. Then، using cross-section method and double staining، the anatomy of root، in terms of cross-section، cortex cells growth and the density of secondary roots، were studied by a light microscope. Results showed that IBA application with or without B1 significantly affected the growth، anatomy and morphology of rosemary cuttings in rooting stage. However، our results clearly showed that vitamin B1 had an essential role on the growth of roots and IBA stimulated cell division in pericycle، causing the stimulation of rooting response of cuttings. According to he obtained results، the combined use of IBA and vitamin B1 showed significant effect on the propagation of rosemary as an ornamental and medicinal plant; therefore، their application could be recommended in commercial and farm conditions، and even in the case of other ornamental plants having difficulty propagating.