Effect of 17β-estradiol on seedling and callus growth of German chamomile (Matricaria chamomilla L.)

To study the effect of 17β-estradiol on seedling growth, antioxidant enzyme activity and also, on callus induction from leaf explants of German Chamomile (Matricaria chamomilla L.), an experiment was conducted as a completely randomized design with three replications using MS medium containing different concentrations of 17β-estradiol (0, 0.01, 0.1, 1 and 10 mg/l) alone or in combination with 3 mg/l Benzylaminopurine (BAP) + 0 or 1.5 mg/l 1-naphthalene acetic acid (NAA). The results showed that 17β-estradiol at 0.01 and 0.1 mg/l increased root and shoot length and weight, respectively and at high concentration (10 mg/l) increased peroxidase, polyphenol oxidase and catalase activity of German chamomile seedlings. Also, the callus induction was observed after one to two weeks in all media, but the growth varied depending on the presence or absence of plant growth regulators and different concentrations of 17β-estradiol. Maximum callus weight was obtained in 0.01 mg/l of 17β-estradiol with about three-fold increase in comparison with the control (MS without17β-estradiol). This indicates that the 17-beta-estradiol at lower concentrations (0.01 mg/l) can significantly improve callus growth in the presence of plant growth regulators such as NAA and BAP. The results of this study indicate that using steroidal hormone 17β-estradiol can be used to optimize German chamomile cell growth under in vitro conditions.