Investigation the efect of drought tension and seed pretreatment on physiological and biochemical traits of Quinoa(Chenopodium quinoa)

In the present research in order to investigate the effect of seed pretreatment on quantitative and qualitative characteristics of quinoa seedlings under drought tension, a factorial experiment was conducted in a completely randomized statistical design with three replications in the research greenhouse of Faculty of Agricultural Sciences of Shahed University in 2019. In this experiment, seed pretreatment was performed at two levels of hydro-priming for 12 hours and bio-priming with bacteria (Bacillus subtilis) for 24 hours and drought tension at five levels of 0, -0.5, -1, -1.5 and -2 Megapascals with Polyethylene glycol. The results showed the effect of pretreatment on all investigated traits except for malondialdehyde content and membrane stability was significant. Application of growth-promoting bacteria led to improvement of quinoa seedling indices such as fresh weight content of shoots (29 gram), chlorophyll content (40.65 microgram per gram), carotenoid (2179.3 microgram per gram), activity of superoxide dismutase enzymes (16.60 milligram per protein) and catalase (3.07 milligram per protein), total phenol (52 mol per gram), flavonoids content (62.65 mol per gram). Increased drought tension resulted in a decrease in shoot fresh weight, carotenoid content, total sugar and protein content, but increased content of chlorophyll, proline, total phenol, flavonoids and catalase enzyme activity rate under drought tension conditions. Also, the dual interaction of pretreatment in drought tension on chlorophyll a content was significant and the highest chlorophyll content (28.05 microgram per gram) was obtained at -2 Megapascals and bio-priming tension. Therefore, biopriming with bacteria is recommended to achieve the highest amount of fresh weight of shoots, enzymatic and non-enzymatic antioxidants of quinoa.