Effects of pre-chilling on germination of Robinia pseudoacacia under salt stress

The imbibed black locust seeds were treated with pre-chilling (3-5℃) for different days (5,10 and 15 d) and their germination capacity under different concentrations of NaCl (0,0.1%,0.2%,0.3%,0.4% and 0.5%) was analyzed.Results show that the germination rate and germination energy of black locust seeds treated with NaCl for 5d increased significantly, and their germination and vigor index were also higher than those of control if NaCl concentration was not more than 0.5%; followed by the seeds treated with pre-chilling for 10 d; the seeds would be injured with a pre-chilling time more than 15 d. During the gemination the activities of superoxide dismutase (SOD) and catalase (CAT) of treated seeds all increased; the activity of peroxidase (POD) was higher (NaCl concentration less than 0.2%) or less (NaCl concentration more than 0.2%) than those of control. These indicate that pre-chilling treatment could improve both the salt resistance and the seedling growth of black locust seeds during the germination.