Effect of different growth regulators levels and explants types of callogenesis and organogenesis Hypericum perforatum L. under in vitro condition

In this study the effect of different levels of plant growth regulators (picloram, 2,4-D, IAA and BAP) and explants type (root, stem and leaf) were examined on callogenesis and organogenesis of st John's wort with factorial experiment design on the basis of completely randomized design with five repeats and five explants. The explants were obtained from 30 days plantlets and transferred to media supplemented with picloram, 2,4-D, IAA (0,. ,, 2 mgl-1) and BAP (0, 0.4, 0.8 mg l-1). Samples were kept in the growth chamber in the darkness condition at 23°C. After 28 days, the interactions between explants types and hormone levels were investigated. The significant effect at the 1 percent probability was observed between treatment levels of 2, 4-D, picloram, BAP and its interaction (2, 4-D * BAP) for the calluses size and shoot numbers. Also the significant effect at the 1 percent probability was observed between treatment levels of IAA, BAP and its interaction (IAA*BAP) for the calluses size, shoot and root numbers. The highest numbers of shoots (83 shoots) were achieved in the leaf explants treated with 0.4 mgl-1 BAP. The highest callus size (5 mm) was observed in media containing 0.5 mg l-1 picloram and 0.4 mg l-1 BAP and stem explants also greatest number (91 roots) of roots were observed in media supplemented with 2 mgl-1 IAA in the leaf explants.