Effects of Plant Growth Regulators on Frequency Shoot Multiplication of an Important Ornamental and Medicinal Plant, Snowbush (Breynia disticha)

The current research was conducted in Mansoura University, Faculty of Agriculture at Vegetable and Floriculture Department in the experimental station and tissue culture laboratory of. This study describes in vitro shoot multiplication from the nodal segments of the ornamental and medicinal shrub Snowbush (Breynia disticha). Multiple shoots were induced directly from the nodal explants on Murashige and Skoog (MS) medium fortified with different cytokinins, i.e., 6-benzyl aminopurine (BAP), kinetin (Kin), thidiazrone (TDZ), 2-isopentenyl adenine (2ip) and coconut water at different concentrations individually or in combination with auxins (indole-3-acetic acid, indole-3-butyric acid, α-naphthaleneacetic acid) or gibberellic acid (GA₃). BAP at a concentration of 0.5 mg/L was found to be the most effective cytokinin in inducing multiple shoots. Using auxins in combination with BAP was less effective on the frequency of shoot multiplication as compared to BAP alone. While, the frequency of shoot multiplication was markedly influenced by adding GA₃ to the media, since the highest percentage of shoot multiplication (100 %) as well as large number of shoots/ explant (4.16 shoots) were obtained with MS medium supplemented with BAP at 0.5 mg/L + GA₃ at 0.1 mg/L. Also, this medium succeeded to induce roots at the same stage with rooting percentage of 50 % and roots number of 4.15 roots. Mixture of soil: peatmoss (1: 1) was suitable planting substrate for hardening the rooted shoots and its use ensured high survival frequency (100 %).