University of Guilan Iranian Journal of Seed Sciences and Research 2476-3780 4 4 2018 02 20 The effect of chilling treatment on physiological traits of germination of three soybean cultivars The effect of chilling treatment on physiological traits of germination of three soybean cultivars 115 130 2522 10.22124/jms.2018.2522 FA Darush Taghavi Karaj Mohammad Sedghi Ardabil Ali Ebadi Ardabil Omid Sofalian Ardabil Aidin Hamidi Karaj Journal Article 2016 11 26 Due to sensitivity of soybean seedlings to cold, in order to study the effect of chilling duration and cultivar on physiological characteristics of soybean seed germination, a factorial trial in random block design with five level of pre-chilling (control, 10, 20, 30, 40 days in 4°C) and three cultivars (JK, Linford and Clean) with three replication was conducted in the seed science and technology laboratory of Mohaghegh Ardebili University in 2014. Traits like the percentage of  germination, germination rate, Sodium (Na) content, Calcium (Ca) content, Potassium (K) content,  Electrical conductivity (EC), soluble sugar content, Catalase and Peroxidase enzyme activity were measured. The interaction of cultivar and pre-chilling was significant on all biochemical traits of seed germination except Peroxidase and Catalase enzyme activity and EC. Highest germination percentage and rate happened in 40 days pre-chilling treatment. The EC of seeds was increased by 27 percent with increase in the duration of chilling from control (no chilling) to 40 days chilling. Cultivar and chilling interaction on inorganic elements Na, K and Ca were significant, the percentage of Na decreased and percentage of K and Ca increased with increase in duration of chilling. 40 days of chilling caused 8.5 percent increase in soluble sugar compare to control (no chilling). The activity of antioxidant enzymes Catalase and Peroxidase, rose with the increase in duration of chilling. The highest activity of Catalase enzyme was gained from the cold resistant cultivar (JK) with 8.507 µM/min*g (fresh weight) and the highest Peroxidase enzyme activity yielded from 40 days chilling treatment with amount of 37.243 µM/min* g (fresh weight). According to the physiological result the 40 days chilling treatment, due to high germination percentage and rate, high antioxidant enzyme activity and soluble sugar, is recommended for sowing and better seedling establishment. Due to sensitivity of soybean seedlings to cold, in order to study the effect of chilling duration and cultivar on physiological characteristics of soybean seed germination, a factorial trial in random block design with five level of pre-chilling (control, 10, 20, 30, 40 days in 4°C) and three cultivars (JK, Linford and Clean) with three replication was conducted in the seed science and technology laboratory of Mohaghegh Ardebili University in 2014. Traits like the percentage of  germination, germination rate, Sodium (Na) content, Calcium (Ca) content, Potassium (K) content,  Electrical conductivity (EC), soluble sugar content, Catalase and Peroxidase enzyme activity were measured. The interaction of cultivar and pre-chilling was significant on all biochemical traits of seed germination except Peroxidase and Catalase enzyme activity and EC. Highest germination percentage and rate happened in 40 days pre-chilling treatment. The EC of seeds was increased by 27 percent with increase in the duration of chilling from control (no chilling) to 40 days chilling. Cultivar and chilling interaction on inorganic elements Na, K and Ca were significant, the percentage of Na decreased and percentage of K and Ca increased with increase in duration of chilling. 40 days of chilling caused 8.5 percent increase in soluble sugar compare to control (no chilling). The activity of antioxidant enzymes Catalase and Peroxidase, rose with the increase in duration of chilling. The highest activity of Catalase enzyme was gained from the cold resistant cultivar (JK) with 8.507 µM/min*g (fresh weight) and the highest Peroxidase enzyme activity yielded from 40 days chilling treatment with amount of 37.243 µM/min* g (fresh weight). According to the physiological result the 40 days chilling treatment, due to high germination percentage and rate, high antioxidant enzyme activity and soluble sugar, is recommended for sowing and better seedling establishment.