Investigation the effects of water defficency stress on the photosynthetic parameters in Salvia plant probed by JIP test

Water defficency stress is one of the most important abiotic stresses that can affect plant growth and development. Salvia is also one of the important medicinal plants that has several medicinal properties. In the present study, the effects of different levels of water deficincy including 25, 50, 75 and 100% of soil field capacity on photosynthetic parameters in two sensitive and resistant species of salvia were investigated by JIP-test method. The results of this study showed that with increasing water defficency stress the number of active reaction centers (RC / CS), the amount of electron transfer in the photosynthetic system (ETo / CS), the efficiency of light reactions in photosystem II (φPo / (-1 φPo)) , Efficiency of biochemical reactions in electron transfer chain (ψo / (1- ψo)), efficiency of electron delivery to photosystem I (δRo / (1- δRo)) and performance index of electron transfer from the beginning of photosystem II to the end of I (PI total) has been reduced and the amount of energy loss in antenna chlorophylls (DIo / CS) has increased. The results of this study also showed that the negative effects of water defficency stress on these parameters in the susceptible species of Salvia (Salvia officinallis) were more than the resistant species (Salvia virgata).