The effects of Seed Treatment on Antioxidant Enzymes Activity and yield of Marigold (Calendula officinalis L.) under drought stress conditions

In order to reduce the damaging effects of drought stress under pretreatment of Marigold seed (Calendula officinalis L.), a factorial experiment under randomized complete block design with three replicates (in place replication) in the field of Urmia Agricultural Research Center and Salmas performed. Experimental factors included irrigation regimes and seed pretreatment, with the first factor irrigated at two levels of regular irrigation and non- irrigation at the beginning of flowering stage and the second factor are seed pretreatment at pre-planting at seven levels including primed seeds with nano fertilizers (Iron oxide, Zinc oxide, Bor oxide was concentrated at 2% per thousand) and primed with organic matter (72 mg humic acid, 2000 μmol salicylic acid and 200 ppm ascorbic acid) and control. Results of analysis of variance showed that the simple effects of seed pretreatment with organic and nano materials on drought stress were significant at 1% probability level. Based on the results of comparison of mean data, oil percentage, oil yield and the weight of one thousand seeds increased with Zinc nano oxide pretreatment by 16, 12 and 8% respectively under drought stress conditions compared to control treatment. Salicylic acid treatment significantly reduced proline accumulation by 13% and soluble protein by 18% compared to control. By applying pre-treatment of nano iron oxide the activity of catalase and peroxidase enzymes increased by 39% and 57% compared to control (non-treated), respectively. Generally, seed pretreatment with different levels of salicylic acid and iron and zinc nano oxide significantly reduced the adverse effects of drought stress on most of the studied traits. Shrubs obtained from seeds treated with salicylic acid, iron nano oxide and zinc nano oxide had higher drought stress tolerance. Results showed that drought tolerance and increase yield of Marigold under drought stress with seed priming with salicylic acid, iron nano oxide and zinc nano oxide are recommended in sustainable and organic farming.