Effects of salt stress on the growth of Bothriochloa ischaemum and its physiological response

Salt stress may be the main factor affecting the distribution of Bothriochloa ischaemum, an important constructive species in Shanxi grasslands. To explore the effects of salt stress on the growth of Bothriochloa ischaemum and its physical responses, B. ischaemum ‘Taihang’ was cultivated using hydroponics and treated with 0, 50, 100, 200, and 300 mmol·L⁻¹ NaCl solutions. The growth potential of the aboveground and underground parts, as well as the membrane permeability, content of osmotic regulating substances, and degree of membrane lipid peroxidation of the aboveground leaves, were measured. The results showed that salt stress had a significant (P < 0.05) inhibitory effect on the growth of B. ischaemum, including the aboveground and underground parts, and the inhibitory effect was enhanced with an increase in salt concentration. The relative electrical conductivity and proline, malondialdehyde, and soluble sugar content in the leaves showed an upward trend with increasing salt concentration. The activity of superoxide dismutase and catalase in leaves increased and then decreased with increasing salt concentration, reaching a maximum of 200 mmol·L⁻¹ NaCl. This study showed that the growth and development of B. ischaemum were inhibited in a high-salt environment.