The effect of steroidal progesterone hormone on seedling growth, antioxidant enzymes and callus induction in German Chamomile (Matricaria chamomilla L.)

In order to study the effect of steroidal progesterone hormone on seedling growth, antioxidant enzyme activity, and also on callus induction from leaf explants of German Chamomile (Matricaria chamomilla L.), an experiment was conducted out based on completely randomized design with three replications using MS medium containing different concentrations of progesterone hormone (0, 0.01, 0.1, 1, and 10 mg/l) alone or with in combination of steady concenteration of 1-naphthalene acetic acid (NAA) and Benzylaminopurine (BAP). The results showed that this hormone at low concentrations (0.01 mg/l) increased seedling length, seedling and root weight and also increased peroxidase and polyphenol oxidase activity in concentrations of 0.1, 1 and 10 mg/l and at concentrations of 0.1 and 1 mg/l increased catalase activity. Although, leaf explants responded to induction of callus after one to two weeks in all media, but its growth were different depending on the presence of phytohormones and concentration of progesterone hormone. The highest callus fresh weight from leaf explants was achieved at 0.01 mg/l concentration of this hormone when used in combination with NAA and BAP phytohormones. This hormone was capable of callus induction from leaf explants when used in the absence of BAP and NAA phytohormones, but growth rate of callus was far lower than that was used in combination with BAP and NAA in the culture medium. The results of this study show that this hormone can be used in optimizing the in vitro growth conditions of plants.