Effects media and drought stress on the biochemical characteristics of evening primrose (Oenothera biennis L.) seed

Evening primrose is an ornamental plant with medicinal properties that almost all organs of this plant, including its roots, leaves, buds, flowers, buds and seeds are edible and used. Evening primrose seeds contain beneficial fatty acids and phenolic compounds that are effective in human health. Numerous factors are involved in the amount and composition of active ingredients in the grain. This study was conducted to evaluate the effect of different culture media, organic fertilizers and drought stress on fatty acids and phenolic content of evening primrose seeds. The experiment was performed in a completely randomized design in 9 treatments with three replications in two years in the greenhouse. Plant seeds were sown in substrates with different compositions of coco peat, perlite, compost, cow manure, vermicompost and farmyard soil under two conditions of drought stress or complete irrigation. The results of analysis of variance showed that the type of substrate used and also the different composition ratios used had a significant effect (P <0.01) on the amount of fatty acids in seed oil except palmitic acid, but on the acid content. Palmitic had little effect. The results showed that the content of phenolic compounds and gammalinoleic acid in the seeds of plants grown in soil was higher than the seeds of plants grown in other substrates. Drought stress also had no significant effect on the content of phenolic compounds in seeds.