Effect of Seed Priming on Quality Improvement of Maize Seeds in Different Genotypes

In Korea, production of super sweet corn has been economically feasible and is substituting for traditional sweet corn due to better flavor in recent years. Major limiting factors for super sweet corn production are low field emergence and low seedling vigor. The optimum water potential (WP) for the priming of normal and aged seeds of dent, sweet (su) and super sweet (sh2) corns was studied to improve low seed quality. Seeds were primed at 0, -0.3, -0.6, -0.9, and -1.2 MPa of polyethylene glycol (PEG) 8000 solution at $15^{\circ}C$ for 2 days. Priming effects differed depending on the type of corn, seed quality, and WP of PEG solution. Although WP of priming solution did not influence the emergence rate of extremely high quality normal dent corn seeds, it reduced time to $50\%$ emergence (T50) and increased plumule weight. In contrast, the emergence rate of aged field corn was improved by seed priming at 0 MPa and plumule weight and $\alpha-amylase$ activity was enhanced. The optimum WP for both normal and aged sweet and super sweet corn seeds was between -0.3 and -0.6 Mpa. At the optimum WP emergence rate, $\alpha-amylase$ activity, and content of DNA and soluble protein increased, while T50 and leakage of total sugars and electrolytes reduced.