Response of Germination and Seedling Growth of Pepper cultivars to Seed Priming by Plant Growth Regulators

In order to study the germination and growth of pepper seeds, a factorial experiment based on a completely randomized design with three replications was conducted. The first factor was consisting of five cultivars of pepper (Marquiza, Cadia, California Wonder, California Wonder 310 and California Wonder 300) and the second factor was gibberellic acid with three levels (0 as control, 250 and 500 ppm), and the third factor was naphthalene acetic acid with three levels (0 as control, 50 and 100 ppm). The results showed that the highest germination percentage (89.9%- California-Wonder 310 cultivar), rate of germination (0.85- California-Wonder 310 cultivar), shoot height (95.99 mm- California Wonder 300 cultivar), shoot fresh weight (6.62 g- California Wonder 300 cultivar) root fresh weight (3.46g- California Wonder 300 cultivar), root length (15.85 cm- Marquiza cultivar), leaf length (5.36 cm-Cadia cultivar) and stem diameter (26.91mm- California Wonder 300 cultivar) were obtained from the concentration of 500 ppm GA3 and 100 ppm NAA. The maximum seed vigor index (749.6) was detected in 0 ppm GA3 and 100 NAA in California Wonder 300 cultivar. The 500 ppm concentration of GA3 and 0 NAA in California Wonder 310 cultivar caused the highest leaf number (3.96). No significant differences were obtained for leaf area and leaf width among all tested concentrations. It can be concluded that seed priming of pepper with plant hormones (GA3 and NAA) is a proper strategy for improving germination and growth traits of pepper plants.