Effect of priming and seed age on germination, photosynthetic pigments, and biochemical content of Quinoa seedling

To investigate the effect of quinine seed priming on morpho-physiological and biochemical traits of seedlings, a factorial experiment was conducted in a completely randomized design with four replications at the seed processing laboratory of the Shahed University of Tehran. Experimental factors included two levels of seed age (one-year old and four-year old) and four priming treatments (control without priming, hydro-priming, salicylic acid with a concentration of 50 ppm and potassium nitrate with a concentration of 0.2 wt% by volume). The effect of seed age on all studied traits was significant at the level of 1% probability. With increasing seed age, germination percentage (45.6%), germination rate (63.43%), seedling length (59.21%), chlorophyll a content (53.1%), chlorophyll b content (67.4%), carotenoids (6 56.6%), soluble sugar (55.8%), protein (47%), anthocyanin (62%) and catalase activity (50%) decreased whereas the amount of electrolyte leakage increased by 25.9%. The effect of priming on all studied traits was significant at the level of one percent probability and improved the studied traits. The interaction effect of seed age and priming on some traits was also significant. Priming of four-year-old seeds with potassium nitrate as the best treatment composition increased Germination percentage (52.67%), Germination rate (about 490%), Shoot length (about 430%), Chlorophyll a content (77.4%), Chlorophyll b content (180%), Carotenoids (92.8%), Protein (200%) and Catalase activity (250%) and 40.2% reduction of Electrolyte leakage from the plasma membrane. According to the obtained results, it can be stated that the use of the potassium nitrate priming method can greatly reduce the effects of ageing and seed deterioration.