Study of phytochemical compounds and essential oil function of Marigold (Calendula officinalis L.) plant under the salinity stress by Nacl with the application of Humic acid and Selenium

The present study was conducted to investigate the phytochemicals and yield of essential oil of Calendula officinalis L. under Nacl-induced salinity stress using acetic acid and selenium as a factorial experiment in a completely randomized design with two factors Nacl-induced salinity stress (Two levels of 50 and 100 mg/L) as the main factor and foliar application of selenium (with two levels of 5 and 10 mg/L) and soil application of Humic acid (with two levels of 50 and 100 mg /L) as side factor and interactions of them. The experiment consisted of 19 treatments each with 3 replicates, each replicate containing 3 plants and a total of 171 pots. Sampling and evaluation of traits were done about 20 days after treatment (flowering stage). The experiment was repeated for two consecutive years for greater confidence and better results. The results showed that in both years control treatment had the highest amunt on traits such as fresh and dry weight of shoot and root, plant height and flower number, petal carotenoid content and total leaf chlorophyll content, protein content, phenol and flavonoid content, and It had a shelf life on the plant. Highest proline content were observed in 100 mg / l NaCl and highest activity of superoxide dismutase and peroxidase enzymes and highest percentage of essential oil were obtained in 50 mg/L sodium chloride + 200 mg/L Humic acid + 50 mg/L selenium. Also in the first and second year, control treatment (10.9 and 11.2 days, respectively) had the highest and treatment with 100 mg/L NaCl with 5.4 and 6.1 days, had the lowest longevity of Marigold flowers on plants.