Effects of chilling stress on physiological and biochemical traits of three hybrid of Corn (Zea mays L.) in seedling stage

This research was performed to study the effects of chilling stress on physiological and biochemical traits (both chilling stress and non-stress control levels) of three-hybrid corn (Zea mays L.) seedlings (single-cross 704, 400, 260) in factorial in a completely randomized design in the research greenhouse of Ferdowsi University of Mashhad, Iran. To apply chilling stress, the four-leaf seedlings have been treated in a room at five degrees Celsius for 12 hours. The chilling stress in two levels of single-cross 260 and single-cross 704 led in malondialdehyde increase, while it decreases in single-cross 400 in the same situation. The concentration of Di-tyrosine was shown 40% higher in single-cross 704 compered to single-cross 260 and 400. In addition, the concentration of superoxide dismutase enzyme in single-cross 260 was significantly higher than two single-cross 700 and 400 hybrids. Glutathione peroxidase represented asignificant effect in different corn hybrids in the presence of chilling stress, which in single-cross 260 chilling stress caused a 39% reduction in glutathione peroxidase while other two hybrids have shown no significant change. Chilling stress caused significantly 20% reduction of catalase enzyme compared to non-chilling condition. The highest amount of catalase enzymes were measured in single-cross 260 which is significantly higher than two other hybrids. Although, chilling stress has no significant morphological effect on corn plants, but the plants exposed to the chilling stress has shown biochemical changes in their antioxidant system and plant cell membrane stability.