ISHS Acta Horticulturae 504: VI Symposium on Stand Establishment and ISHS Seed Symposium
STUDIES ON SEED DORMANCY: SEEDS MATURATION IN RELATION TO DORMANCY IN GOLDENRAINTREE (KOELREUTERIA PANICULATA LAXM.) |
| Authors: | I.-H. Park, S. Rehman |
| Keywords: | Chilling, dormancy, germination, goldenraintree, gibberellic acid, Koelreuteria paniculata Laxm |
| Abstract:
Goldenraintree (Koelreuteria paniculata Laxm.) seeds exhibit both seed coat and embryo dormancy. Seeds harvest consisted of green (G), half-matured (HM) and fully-matured (FM) seeds with 100, 58 and 12% moisture per gram dry weight, respectively. Unscarified and manually-scarified seeds were treated with 300 mg.L-1 gibberellic acid (GA) solution or moist chilled at 4°C for 1, 2 or 3 months. GA reduced or had no effect on the germination of G and HM seeds, while the germination of scarified FM seeds was increased. Similarly, chilling had no effect on the G seeds. Chilling for 1 month increased the germination of HM seeds but chilling for more than 1 month proved harmful. On the other hand the germination of unchilled HM seeds (dry stored) increased continuously over 3 months of storage. FM seed germination was increased after 2 and 3 months of chilling, with no difference between 2 and 3 months. In order to test the interaction of seed moisture content and dormancy, the G and HM seeds were dried to 50% of their original moisture contents. It was observed that after drying, the germination of G and HM seeds was increased from almost zero to a maximum of 86% and from 2 to a maximum of 75%, respectively. The ineffectiveness of GA and cold treatment on the G seeds may be due to the anaerobic conditions created by the high moisture contents of the seeds and moist chilling. It may also be possible that in the absence of a desiccation period the G seed continued developmental growth. In the case of HM seeds, moist chilling for a long period may have created a water-logged environment and the seeds probably entered a state of secondary dormancy. The results that G and HM seeds have no seed coat dormancy while FM seeds have seed coat as well as embryo dormancy. | |
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