How Hormonal Priming of Aged and Nonaged Seeds of Bromegrass Affects Seedling Physiological Characters

Abstract

Effects of hormonal priming by cytokinin (CK), auxin, and gibberellin (GA) at 0, 25, 50, and 100 ppm of aged and nonaged seeds of bromegrass (Bromus inermis) on some physiological properties of seedlings were evaluated in a pot experiment. The seeds were subjected to accelerated aging to produce aged seeds. Percentage and rate of seedling emergence, seedling vigor, seedling-growth rate (SGR), seedling dry weight, chlorophyll and activity of catalase and peroxidase of seedling decreased following accelerated aging. Auxin priming improved emergence, vigor, SGR, root length, shoot, and seedling height. CK produced largest leaf area, whereas GA-primed seed had the highest concentration of chlorophyll in seedlings. Results suggested that physiological quality of bromegrass seed, especially aged seed, could be improved by hormonal priming. Auxin had the most positive effect on percent emergence, rate of emergence and SGR; CK and GA had positive effects on chlorophyll and leaf area. The three phytohormones in ap...