EFFECT OF SULPHURIC ACID SCARIFICATION, COLD MOIST STRATIFICATION AND GIBBERELLIC ACID ON GERMINATION OF PALIURUS SPINACHRISTI MILL. SEEDS

Paliurus spina-christi seeds were subjected to several treatments in order to overcome dormancy and to maximize germination. Seeds were subjected to sulphuric acid scarification for 0, 30, 60 and 90 minutes and then were stratified at 3–5oC for 0, 4, 8 and 12 weeks (1st experiment) or treated with 500, 1000 and 2000 ppm gibberellic acid (2nd experiment). In the first experiment, increasing scarification of non-stratified seeds from 30 to 60 or 90 minutes germination percentage increased significantly. Moreover, cold stratification treatments of non-scarified seeds resulted in very low germination percentages. The combination of acid scarification and cold stratification treatments improved significantly germination percentages. In the second experiment, treatment with gibberellic acid, regardless of concentration, of scarified seeds improved significantly germination percentages. The concentration of gibberellic acid was found to effect germination only in 30 minutes scarified seeds. In treated seeds with 500 or 1000 ppm gibberellic acid, a significant increase of germination percentage together with the increase of time of scarification from 30 to 60 or 90 minutes was observed. The results revealed that scarification was more effective than cold stratification in improving seed germination when treatments were applied alone. The highest germination percentages were observed when acid scarification was followed by cold stratification or treatment with gibberellic acid.