| heal.abstract |
The effect of osmopriming on germination performance of cottonseeds was investigated under suboptimal thermal conditions (12 to 24°C). Seeds were primed in mannitol solutions at three water potentials (-0.5, -1.0 and -1.5 MPa) for 6, 12 or 18 hours at four incubation temperatures (16, 19, 22 and 25°C) in darkness. The treated seeds and non-primed controls were then subjected to germination tests at 12, 15, 18, 21 and 24°C Germination performance was evaluated by final germination percentage, time to reach 10, 50 and 90% germination, germination uniformity, and thermal time requirement. Osmotic potentials of -0.5 MPa and, to a lesser extent -1.0 MPa, tended to increase germination rate and uniformity in comparison with non-primed seeds. In addition, osmopriming resulted in a substantial lowering of the thermal time requirements for seed germination. In most cases, seed performance based on all the parameters considered was better for priming durations of 6 or 12 hours than for 18 hours. A trend for higher germination uniformity was apparent when seeds were primed at 19 and 22°C. |
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