Evaluation of Thyme (Thymus vulgaris L.) seed germination responses under different priming treatments

AbstractObjective of this research was identification and determination of the most suitable treatments to improve seed germination characteristics of Thyme medicinal plant. In order to evaluate different priming treatments on seed germination characteristics of Thyme, an experiment was conducted in a completely randomized design with four replications which treatments were: without priming (control), Gibberellic acid (100, 200 and 300 ppm), Cytokinin (200 and 400 ppm), thiourea (1000, 2000 and 3000 ppm), potassium nitrate (10, 20, 100, 200, 300 and 400 ppm), phosphorus (10, 20, 30 ppm), manganese sulfate (2, 4 and 6 ppm). Germination characteristics such as shoot and radicle length, germination percentage, seed vigor, mean germination time and germination rate were evaluated. The results showed significant effects of seed priming treatments on shoot and radicle length, germination percentage, seed vigor and mean germination time at 1% probability level and germination rate at 5% probability level. Among the treatments, gibberellic acid treatments (100 ppm) and potassium nitrate (200 ppm), thiourea (2000 ppm) and manganese sulfate (4 ppm) presented high positive impacts on germination. Cytokinin treatments also significantly decreased many germination characteristics. It seems that potassium nitrate and gibberellic acid treatments compared with other treatments are more effective to improve all thyme germination characteristics.