Methods of breaking seed dormancy in Caper (Capparis spinosa L.)

This study was conducted to study the effect of seed dormancy breaking on seed germination of Caper (Capparis spinosa L.), in a completely randomized design with four replications. Treatments of seed dormancy breaking in Caper included: untreated seeds (control), scarification with concentrated sulphuric acid for 20 minutes, soaking in gibberellic acid (500 and 1000 ppm), Potassium Nitrate (0.3%), leaching for 12 hours and combined treatment (leaching for 12 hours and soaking in gibberellic acid (500 and 1000 ppm), leaching for 12 hours and soaking in Potassium Nitrate and scarification with sulphuric acid and soaking in gibberellic acid (500 and 1000 ppm). The results showed significant differences among seed dormancy-breaking methods. According to the results, the highest seed germination percentage of caper was observed in combined treatment (leaching for 12 hours and soaking in gibberellic acid 1000 ppm (98%) and leaching for 12 hours and soaking in gibberellic acid 500 ppm (75%). Our results showed that the treatment of seed leaching for 12 hours reduced the formation of mucilage around the seed and caused an increase in seed germination. Moreover, application of gibberellic acid or Potassium Nitrate could be just useful when the mucilage concentration of the seed coat is reduced by leaching.