Physiological Responses of Grafted Morus alba ‘Jisang 2’ Seedlings to NaCl Stress

Scions of Morus alba ‘Jisang 2’ were grafted in stocks of M. alba ‘Jisang 3’ in April of 2014 in Chengde, Hebei province. Grafted seedlings were transplanted in pot under rain-proof shed in the April of the next year. In June of 2015, seedlings were treated with 0 (control)，0.2%， 0.3% and 0.4%NaCl solutions of NaCl for 28 days, and physiological parameters were detected each 7 days after treatment. The results showed that relative conductivity and malondialdehyde (MDA) content in leaves of M. alba ‘Jisang 2’ increased with stress duration of NaCl, while the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) increased first and then decreased, as well as the content of free proline and soluble sugar, and soluble protein decreased.