Caulogenic Efficacy of Cytokinin in Internodal Explants of Rosmarinus officinalis L. as Affected by Auxin and Inorganic Salts*

Caulogenesis took place in internodal stem segments of Rosmarinus officinalis in the presence of both 6-benzylamin-opurine (BAP) and 3-indoleacetic acid (IAA). There existed a synergism between BAP and IAA, where lower concentration of 0.1 mg/l IAA increased the shoot bud inducing efficacy of BAP to about ten times, while at 0.25 mg/l IAA it was counteracted. Presence of both NH₄NO₃ and KNO₃ was essential for shoot bud differentiation. While caulogenesis greatly declined if any of the inorganic salts was lacking in the medium, it increased in the absence of CaCI₂. The regeneration potentiality of the first internode was more than the second internode and within the internode it was more in the upper end than the lower. Shoot meristems differentiated from the subepidermal tissue from the meristemoids, which were formed in close proximity with nests of tracheary tissue. There was no direct regeneration from the epidermal cells.