EFFECTS OF SULPHURIC ACID SCARIFICATION, COLD STRATIFICATION AND PLANT GROWTH REGULATORS ON THE GERMINATION OF Rhus coriaria L. SEEDS

摘要

The present study investigates the effects of various dormancy breaking treatments, namely, sulphuric acid scarification, cold stratification as well as gibberellic acid (GA(3)) and ethephon application, on Rhus coriaria seed dormancy release. Following treatments, the seeds were incubated to germinate at 20 degrees C for 16 h in the dark, and at 25 degrees C for 8 h in the light. The seeds (true seed plus endocarp), which were only cold stratified at 3-5 degrees C (up to 4 months) or only H2SO4-scarified (up to 180 min), exhibited very low germination percentages. Soaking seeds in H2SO4 for 180 min resulted in significant reduction of germination due to loss of seed viability. The combinations of H2SO4 scarification and cold stratification treatments significantly improved seed germination. In H2SO4-scarified (60 min) seeds, the treatment with GA(3) (regardless concentration) was found to enhance germination significantly only in non-stratified and one-month stratified seeds, whereas ethephon was not found to improve germination. The present study demonstrated that of R. coriaria seeds displayed a combination of physical and physiological dormancy.