PEG6000渗透胁迫对鸟巢蕨生理指标的影响

Effect of PEG6000 osmotic stress on physiological indexes of Neottopteris nidus (L.) J.Sm.

研究在聚乙二醇6000(PEG6000)室内模拟干旱条件下,比较不同浓度PEG渗透胁迫对鸟巢蕨的叶片相对含水量、可溶性糖含量、过氧化物酶活性、丙二醛含量以及游离脯氨酸量5个生理指标的影响.结果表明:鸟巢蕨叶片相对含水量与胁迫程度呈负相关;复水后各浓度处理下的叶片含水量不能够恢复.丙二醛含量、游离脯氨酸量与胁迫程度呈正相关.复水后各浓度处理下的丙二醛含量不能够恢复,游离脯氨酸含量恢复到对照水平,可溶性糖均随着胁迫的时间延长而累积,20%浓度胁迫12h时达到峰值105.31mg/g,是参与鸟巢蕨渗透调节的主要物质之一,过氧化物酶活性呈先升高后降低的变化趋势,复水后降低至与对照组相近水平;说明鸟巢蕨逆境条件下,过氧化物酶上升到一个较高水平,减轻膜伤害程度,但随着膜伤害程度加深,过氧化物酶不能够在发挥作用.综合各项生理指标的分析认为,鸟巢蕨抗旱能力较差.

Under the condition of indoor simulation drought with PEG6000,the research was conduced to compare the influence of osmotic stress of PEG6000 with different concentrations on the relative water content,soluble sugar content,peroxidase（POD）activity,malondialdehyde content and free proline content of Neottopteris nidus（L.）J.Sm leaves.The results showed that the relative water content of leaf was negatively correlated with stress level.Under the treatment of various PEG6000 concentrations,the RWC would not recover even after watering.Malondialdehyde content and free proline content were both positively correlated with stress levels.After watering,malondialdehyde content of each treatment would not restore,while free proline content returned to control levels.Soluble sugars accumulated with stress time,which reached to peak value of 105.31mg/g after stressed under 20% concentration for 12 hours,and it was the main material involved in the osmotic adjustment of Neottopteris nidus（L.）J.Sm.Activity of peroxidase increased first and then decreased,lowered closely to the control group after watering.It was indicated that in adversity conditions,peroxidase（POD）of Neottopteris nidus（L.）J.Sm increased to a high-er level to relieve membrane damage,however,peroxidase（POD）could not continue to play a role when the membrane damage getting worse.Based on the analysis of the physiological indexes,we concluded that the drought-resistant ability of Neottopteris nidus（L.）J.Sm was week.The study could provide theoretical basis for the moisture management of Neottopteris nidus（L.）J.Sm.