大穗结缕草幼苗耐盐生理机制及耐盐能力研究

摘要

The effect of various concentrations of NaCl on physiological and biochemical index of Zoysia macrostachya seedlings were examined.The results showed that the average height,fresh weight and dry weight of the whole plant decline with the increase of NaCl concentration in medium,but root capacities and ratio of the root/shoot fresh weight are increasing.As well as,the plasma lemma permeability,the malondialdehyda (MDA) content and proline content of Z.macrostachya seedling leaves increase gradually with the increase of NaCl concentration.Most of growth and physiology indices are significantly different with CK on the 2.0% salt concentration.These results suggest that the effect of salt stress lies in the upper part of Z.macrostachya on the ground;By the use of accumulated proline in the body to reduce osmotic stress is a possible physiological mechanism of salt-tolerance;2.0% salt stress may be the extreme salt-tolerance for Z.macrostachya seedlings.%以大穗结缕草为实验材料,采用不同质量分数的NaCl处理后,观察盐胁迫对其生长及生理生化指标的影响.结果表明:随着盐胁迫浓度增大,大穗结缕草幼苗株高、鲜重、干重都逐渐下降,而根容量和根冠比却逐渐上升;随盐胁迫浓度的增大,大穗结缕草幼苗叶片细胞质膜透性和MDA含量逐渐增加,脯氨酸含量持续升高;其多数生长和生理指标在≥2.0% NaCl盐胁迫浓度下与对照差异显著,且此时的脯氨酸含量是对照的10倍以上.研究发现,大穗结缕草幼苗地上部分对盐胁迫更敏感、受害更严重;通过体内脯氨酸积累来减轻渗透胁迫是其可能的耐盐生理机制;2.0%盐胁迫可能是大穗结缕草的最高耐盐浓度.