Origanum is one of the most important medicinal plants used worldwide due to the economic importance, quantity and quality of essential oil and antioxidant properties. Drought is one of the major abiotic stresses that cause deleterious damage to plants. As a bio-elicitor, chitosan prevents severe damage to plants under stress conditions by triggering plant defense mechanisms. To investigate the effects of chitosan application and water deficit stress on growth, yield and secondary metabolites of origanum, a greenhouse study was performed in a factorial experiment based on randomized complete block design (RCBD) with three replications. The studied factors consisted of foliar application of chitosan at three levels (0, 250 and 500 mg/L), under well-watered and water deficit stress conditions in two origanum species (Origanum majorana and Origanum vulgare). The application of water deficit stress and foliar treatment with chitosan (three steps) was performed three weeks before flowering. Results showed that the water deficit stress reduced the plant dry weight, while increased total phenol and essential oil contents. However, foliar application of chitosan at 500 mg/L under water deficit stress conditions increased dry weight of shoots, and phenol content. Application of chitosan at 250 mg/L increased the content of essential oil compared to the control. Results also showed that application of chitosan as a bio-elicitor can reduce the adverse effects of water deficit stress on marjoram plant. The analysis of GC/MS apparatus revealed that 33 compounds were identified in essential oil, in which γ‑terpinene, cis-sabinene hydrate and terpinolene were the dominant in the oil of both origanum species.

由于精油的经济重要性，数量和质量以及抗氧化性能，牛至是全世界使用的最重要的药用植物之一。干旱是对植物造成有害损害的主要非生物胁迫之一。作为生物引发剂，壳聚糖可通过触发植物防御机制防止在胁迫条件下对植物的严重破坏。为了研究壳聚糖的施用和水分亏缺胁迫对牛至的生长，产量和次生代谢产物的影响，在一项基于随机完全区组设计（RCBD）的析因实验中进行了温室研究，该实验进行了三次重复。研究的因素包括在两个牛至属植物的水分充足和缺水胁迫条件下，以三种水平（0、250和500 mg / L）叶面施用壳聚糖（牛至和牛至）。开花前三周进行缺水胁迫和壳聚糖叶面处理（三步）。结果表明，水分亏缺胁迫降低了植物的干重，同时增加了总酚和精油的含量。然而，在缺水胁迫条件下叶面施用500 mg / L的壳聚糖会增加枝干重量和酚含量。与对照相比，壳聚糖250 mg / L的使用增加了精油的含量。结果还表明，壳聚糖作为生物引发剂的应用可以减少缺水胁迫对马郁兰植物的不利影响。GC / MS仪器的分析表明，在香精油中鉴定出33种化合物，其中γ-萜品烯，顺式-大麻素水合物和萜品油烯是两种牛至属植物油中的主要成分。