【Object】The present experiment was conducted to explore the adaptability of Flemingia philippinensis seeds under adverse environmental conditions, especially the low temperature for selecting suitable seeding period. 【Method】The Flemingia philippinensis seeds were cultured at appropriate temperature for 15 days after treatment of cold imbibition and low temperature (6℃) stress for 12, 48, 72 h (after 2 days culture at optimum temperature). The germination indices and physiological parameters such as soluble sugar and protein content, and activities of superoxide dismutase (SOD) and peroxidase (POD) were determined during seed germination. 【Result】The germination rate of seeds stressed for 72 h at low temperature and cold imbibition, and the germination index and average germination rate of seeds stressed for 48 and 72 h at low temperature and cold imbibition were significantly lower than that of control. The soluble sugar, proline and soluble protein content in seeds increased under different low temperature stress compared to control. During seed germination, the POD activity in seeds did not showed any specific trend. In low temperature treatment of 12 h, it initially increased and then decreased, while in 48 and 72 h low temperature treatments it showed an increasing trend initially and then remained constant. The SOD activity in seeds treated with 48 and 72 h low temperatures also not showed any specific trend, however, it was lesser in control and seeds treated with 12 h low temperature. 【Conclusion】It may be concluded that the antioxidative defense system and osmosis adjustment in germinating seeds varied in response to low temperature stress within a certain period. However, cold imbibition stress not only seriously affected the germination of seeds, but also resulted in severe and irreversible damages in protective enzyme defense system of membrane.
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