NaCl胁迫对3种木兰科植物幼苗 叶片部分生理指标的影响
Effect of NaCl stress on some physiological indexes of leaves of seedlings of three species in Magnoliaceae
Abstract | The changes of some physiological indexes of leaves of seedlings of three species in Magnoliaceae (including Magnolia denudata Desr., Magnolia biondii Pampan., and Michelia chapensis Dandy) under 0 (the control), 100, 200, and 300 mmol·L-1 NaCl stresses were studied by nutrient solution culture method. The results show that with increase of NaCl concentration, chlorophyll content in leaves of M. denudata and M. biondii seedlings first increases and then decreases, while that of M. chapensis seedlings decreases, in which, chlorophyll content of three species under high concentration (300 mmol·L-1) of NaCl stress decreases significantly compared with the control. With increase of NaCl concentration, relative electric conductivity, and contents of malondialdehyde, soluble sugar, and soluble protein in leaves of seedlings of three species generally increase, in which, relative electric conductivity and malondialdehyde content under each concentration of NaCl stress are significantly higher than those of the control, and there is no significant difference in contents of soluble sugar and soluble protein with those of the control. With increase of NaCl concentration, proline content and activities of superoxide dismutase (SOD) and peroxidase (POD) in leaves of seedlings of three species first increase and then decrease, in which, compared with the control, proline content of three species under medium concentration (200 mmol·L-1) of NaCl stress increases significantly, and activities of SOD and POD of three species under low (100 mmol·L-1) and medium concentrations of NaCl stress increase in different degrees. It is suggested that seedlings of three species tested in Magnoliaceae have a certain tolerance to low and medium concentrations of NaCl stress, while their cell membranes of leaves are irreversibly damaged under high concentration of NaCl stress. |