The influence of medium solidifying agents and double-phase medium on the growth and development of Cosmos atrosanguineus (Hook.) Voss in vitro

Influence of different medium gelling agents (Agar-Agar Sigma, Lab-Agar TM Biocorp, Bacto-Agar Difco, Gelrite) and two types of medium (solidified by Agar-Agar and double-phase medium) on branching and growth of Cosmos atrosanguineus shoots was investigated. Shoot tips obtained from aseptical tissue cultures were grown for 6 weeks on Murashige and Skoog medium containing BA in concentration of 1 mg dm -3 . It was found that induction of axillary shoots was the best on double-phase medium (addition of liquid medium after 4 weeks of shoot cultures in vitro). No significant differences were found in regeneration potential and elongation of shoots depending of the media solidified by studied agars or Gelrite.