Study of seed dormancy breaking and germination charactristics in Arctium lappa

Arctium lappa is a medicinal plant of Asteraceae. Seeds have a little germination due to seed dormancy. In order to break dormancy and increase the germination of its seeds an experiment with 28 treatments in a completely randomized design with four replications (25 seeds). Treatments were consisting of chemical scarification with sulfuric acid solution 98% for 10 and 20 min, hormone treatments of 24 and 48 hours of Gibberellic acid (GA3) (300 & 500 ppm), moist prechilling for 7 and 14 days at +5 °C temperature, and combined moist prechilling and hormonal treatments, hot water (70 °C, for 10 and 15 min.) humic acid (54 kg/L). Results showed that the effect of treatments on percentage and rate germination of Arctium lappa was significant (P≤%5). The maximum coleoptile length, radicle length, seedling length, germination percentage and germination ratio was related to 14 days moist prechilling treatment with GA3 (500 ppm- 48h) (98/78 %). On the basis of the results and with regard to the negative effect of H2SO4 and hot water on the consequential growth of seedlings, usage of 14 days moist prechilling accompanied with application of GA3 was appropriate.