Effects of Plant Growth Regulators on Direct Shoot Regeneration from Shoot Apical Explants in Four Genotypes of Matricaria chamomillaL

Chamomile (Matricaria chamomilla L.) is a well-known medicinal plant species from Asteraceae family mentioned in 26 countries pharmacopoeia. The aim of this research is to find the best landrace, explants, hormonal combination and environmental condition for the possibility of German chamomile regeneration under in vitro conditions. In this experiment the effect of different concentrations of BAP (4.4 and 8.8µM) and Thidiazuron (TDZ) (4.4 and 8.8µM) in combination with 2.2 µm IAA were evaluated with different landraces (Isfahan, Urumia, Oshnavieh and Shahindegh). The results indicated that Isfahan landrace had the highest regeneration rate (92.48%) on media supplemented with BAP (4.4 µm) in combination with IAA (2.2 µm). The maximum mean number of shoots (25 shoots per explants) obtained in genotype landrace on media containing BAP (4.4 µm) in combination with IAA (2.2 µm). For evaluating of Basal media and plant growth regulators on rooting of regenerated shoots, MS and 1/2 MS medium with (0.5, 1 mg/l) IBA and IAA were used. Result of rooting experiment showed that maximum rooting rate (100%) was occurred on hormone free 1/2 MS medium and MS medium supplemented with 0.5 1mg/l IBA. More than 90% of the regenerated plants were successfully acclimatized and transferred to the greenhouse.