关键词: 刺榆, 种子萌发, 盐胁迫, 生理响应

Abstract: In order to study the response of Hemiptelea davidii seeds and seedlings to salt stress, seed germination of H. davidii was carried out on the petri dish and the seedling culture was carried out by pot experiment. Germination rate, germination potential, germination index, vigor index, relative salt damage rate of H. davidii seed were tested under treatments with NaCl、Na2SO4、Na2CO3 and NaHCO3, as well as malondialdehyde (MDA), superoxide dismutase (SOD) and peroxidase (POD) of H. davidii seedlings. The results showed that：① Under salt concentration range of present work, the seeds of H. davidii can germinate normally under the salt stress treatments of NaCl concentration <30 mmol·L-1, Na2CO3 concentration <10 mmol·L-1, Na2SO4 concentration <20 mmol·L-1 and NaHCO3 concentration <20 mmol·L-1. NaHCO3 and Na2CO3 were more harmful than neutral salts of NaCl and Na2SO4. ②The relative salt damage rate of H. davidii seeds was all greater than 0. The four salts all inhibited seed germination, but the extent was different and showed a tendency of NaCl<Na2SO4<NaHCO3<Na2CO3. ③During the growth of seedlings, MDA content in leaves of different treatments increased gradually. The activities of SOD and POD increased first then decreased with the increase of salt concentration. However, MDA content and activities of SOD and POD of H. davidii seedlings did not change significantly, when NaCl concentration <30 mmol·L-1, Na2CO3 concentration <10 mmol·L-1, Na2SO4 concentration <10 mmol·L-1 or NaHCO3 concentration <20 mmol·L-1. It was suggested that seed germination and seedling growth of H. davidii had certain tolerance to low level salt stress, but high level salt stress will inhibit seed germination and hinder seedling growth of H. davidii. The present work provided theoretical basis for the cultivation and promotion of H. davidii in saline-alkali soil.

Key words: Hemiptelea davidii, seed germination, salt stress, physiological response