外源甜菜碱对低温胁迫下结缕草生理特性的影响

甜菜碱作为一种重要的渗透调节物质,与低温胁迫下植物的抗逆性有着密切的联系。为了探讨不同浓度外源甜菜碱对低温胁迫下结缕草相关生理指标的影响,本实验以结缕草‘青岛’品种为实验材料,分别采用0,50,100和150 mmol/L 的甜菜碱进行叶面喷施,在8/2℃(白天/夜间)的培养箱中连续处理28 d,以正常管理(28/24℃)作为对照。结果表明:外源甜菜碱能够有效缓解低温胁迫下结缕草坪观质量和叶绿素含量的下降,减少电解质渗透率和丙二醛含量的升高,显著提高SOD、POD、CAT和APX的活性,从而降低H₂O₂和O2·-的累积,同时,外源甜菜碱还可以提高低温胁迫下结缕草可溶性蛋白和脯氨酸的含量,增强渗透调节能力,进而增强结缕草对低温胁迫的抵抗性。其中,外施100 mmol/L甜菜碱对提高结缕草的耐低温能力的效果最为显著。

Effects of exogenous glycine betaine on the physiological characteristics of Zoysia ja-ponica under low-temperature stress

Glycine betaine (GB)is an important compatible solute that is associated with stress tolerance in plants under low-temperature stress.To investigate the effect of exogenous GB on the physiological indexes of Zoysia japonica under low-temperature stress,GB at 0,50,100,and 150 mmol/L was applied as a foliar spray to ‘Qingdao’,a Z .japonica cultivar,before transferring the plants to growth chambers.The plants were grown under average temperatures of 8℃/2℃ (day/night)for 28 days in the low-temperature treatment, and under average temperatures of 28℃/24℃ (day/night)in the control.Exogenous GB alleviated the loss of turf quality and chlorophyll content,and reduced the increase in electrolyte leakage and malondialdehyde con-tent in Z .japonica under low-temperature stress.Exogenous GB increased the activities of superoxide dis-mutase,peroxidase,catalase,and ascorbate peroxidase,leading to lower H2 O2 and O2 ·- contents.Also,ex-ogenous GB enhanced the osmotic adjustment capacity of the plants by increasing the concentrations of proline and soluble protein.These results indicated that exogenous GB enhanced the resistance of Z .japonica to low-temperature stress,and 100 mmol/L exogenous GB was the most effective concentration.