Evaluation of Ziziphora tenuior L. growth, oil yield and pulegone content after in vitro slow growth storage

Abstract

Ziziphora tenuior L. is a medicinal plant species which has been used for treatment of many diseases due to the presence of many valuable medicinal ingredients such as, pulegone. This valuable plant has become extinct from its natural environment due to illegal collection, urbanization, overgrazing and drought. In this research, in vitro slow growth storage was applied to study the possibility of conserving Ziziphora tenuior L. microshoots using elevated levels of different sugars or ABA. Also, the effect of slow growth storage on the total oil content and pulegone concentration of the microshoots was investigated after being stored for 3 months. The results revealed that, microshoots prestored in MS media + (0.2 M) sucrose or ABA were able to reduce the all measured growth parameters and to maintain recovery after storage. On the other hand, using sorbitol or mannitol had a strong negative impact on recovery after storage. Meanwhile, there were differences between the amounts of total oil yield and pulegone extracted from the wild type plants and the in vitro prestored microshoots. The maximum amount of total oil yield (5%) and pulegone (0.0312 M) were obtained from the wild type plants. On the other hand, the amount of total oil yield extracted from the in vitro stored microshoots were one third the amounts of oil obtained from the wild type plants. Also, the concentration of pulegone found in the dried in vitro stored samples (0.0041-0.0046 M) was about the same in all in vitro prestored microshoots but much lower than those obtained from the wild plants samples