Effect of gibberellin and indole-3-butyric acid on germination indices and vigor of scallion (Allium fistulosum) seeds

Scallion (Allium fistulosum) is one of the essential edible vegetables with various medicinal uses. The seeds of this plant have low germination power, which may disappear due to storage conditions. In this study, the germination characteristics of scallion seeds were experimented with a factorial arrangement based on a completely randomized design with three replications in the physiology laboratory of Khorasan Razavi Agricultural and Natural Resources Research and Education Center in 2019. The first factor was indole-3-butyric acid (IBA) at 0 (or control), 100, and 200 ppm, and the second factor was gibberellin (GA3) at the same concentrations. The results showed that the maximum germination percentage was obtained by 200 ppm of gibberellin without using IBA. The maximum rootlet dry weight (7.02 mg) was recorded with 100 ppm of GA3 and IBA. The maximum allometric coefficient was obtained using 100 ppm IBA and 200 ppm GA3. The maximum seed vigor index was observed at 100 and 200 ppm of GA3 with 0 ppm of IBA (2.18 and 2.33, respectively). The maximum seedling vigor length index (0.799) and seedling vigor weight index (6.77 ) were obtained when 200 ppm of GA3 was applied with 0 ppm of IBA. In general, the results showed that the use of different concentrations of gibberellin has a significant effect on increasing germination and vigor index in scallion seeds.