Investigating the effect of Different Planting Substrates on the some of the morphological and physiological characteristics of the German chamomile (Matricaria chamomilla) under salt stress

In the situation where Iran is severely suffering from the lack of freshwater resources and the water resources crisis is a serious issue, paying attention to non-conventional water sources is an unavoidable necessity, in which case environmental tensions will occur. Especially salinity becomes important. To investigate the effects of salinity stress in German chamomile with the use of different culture media, factorial research was carried out in the form of a completely randomized design with three replications. In this experiment, two factors of salinity stress (Sa) (0, 50, 100, and 150 mM) and different percentages of culture medium (perlite 100%, cocopit 25%+perlite 75%, cocopit 50%+perlite 50%, cocopit 75%+perlite 25%, and cocopit 100) %) was investigated. The investigated morphological and physiological traits included fresh and dry weight of root and shoot, stem diameter, amount of chlorophyll a and b and total chlorophyll. The results showed that all investigated traits were subjected to salinity stress and showed a significantly decrease compared to the control. The culture medium containing 75% cocopeat and 25% perlite increased the fresh weight of roots by 22.11% compared to the culture medium containing 25% cocopeat and 75% perlite. Also, the control treatment had a 96.08% increase in root fresh weight compared to salt stress with a concentration of 150 mM. Regarding the amount of total chlorophyll, the results showed that Co50Pe50+Sa0, and Co75Pe25+Sa0 treatments were the most (3.93 and 4.01 mg per gram of fresh tissue, respectively) and Co0Pe100+Sa150, Co25Pe75+Sa150, Co50Pe50+Sa150 treatments. Co100Pe0+Sa150 had the lowest (respectively 2.01, 2.02, 2.06, and 2.19 mg per gram of fresh tissue). In general, it can be said that the German chamomile plant in the culture medium containing 75% cocopeat + 25% perlite can withstand severe salt stress and have acceptable growth.