水分胁迫对刺五加幼苗光合生理特性的影响

 通过对刺五加（Acanthopanax Senticosus）幼苗的盆栽实验,模拟4个土壤水分梯度（对照、轻度水分胁迫、中度水分胁迫和重度水分胁迫）下,刺五加幼苗的光合色素、光合作用以及脯氨酸和丙二醛含量的变化特性。结果表明:光合色素含量随水分胁迫程度的加强呈下降的趋势,中度和重度水分胁迫组的光合色素含量较低,均显著低于对照组,而轻度水分胁迫组的光合色素含量与对照组差异不明显,且一直保持很高水平。各组的叶绿素与类胡萝卜素含量比值在3.02～3.65之间波动。在轻度的水分胁迫环境下,其净光合速率未受到显著影响,保持与对照组一致的较高水平,其蒸腾速率较低,比对照组下降27.25%,而水分利用效率比对照组增加26.97%。在中度水分胁迫环境下,刺五加幼苗表现出了较低的净光合速率和蒸腾速率以及较高的水分利用效率,与对照组相比,净光合速率下降29.46%,蒸腾速率下降50.67%,水分利用效率升高33.70%;重度的水分胁迫下的净光合速率和蒸腾速率均处于最低水平,但此时水分利用效率却最大,高出对照77.51%。在整个实验期,叶片脯氨酸和丙二醛含量随着干旱胁迫强度的增加和胁迫时间的延长而持续上升。研究表明,刺五加幼苗具有一定的抗旱能力,但不适应相对干旱的土壤水分环境。研究结论为人工栽培刺五加提供了科学依据。

Influence of water stress on the photosynthetic and physiological characteristic of Acanthopanax senticosus seedings

In order to offer scientific base for the artificial cultivation of Acanthopanax Senticosus,the response of photosynthetic pigment,photosynthesis,content of proline and malondialdehyde(MDA) of Acanthopanax Senticosus seedings to soil water stress were studied using a pot cultivation experiment.Four soil water treatment levels were normal growth water condition(CK),mild water stress (T1),moderate water stress(T2),severe water stress(T3).The results showed that content of photosynthetic pigment decreased as the water stress degree was increased,T2 and T3 had the lower content of photosynthetic pigment than CK,T1 did not differ from CK and kept high level.The ratio of chlorophylls to carotenoids in four groups was ranged 3.023.65.In group T1 the seedlings of Acanthopanax Senticosus did not differ from CK in net photosynthesis rate,with the transpiration rate 27.25% lower than that of group CK and the water use efficiency 26.97% higher than that of group CK;In group T2 the seedlings of Acanthopanax Senticosus had lower net photosynthesis rate、transpiration rate and higher water use efficiency than that of group CK,with the net photosynthesis rate decreased 29.46%,the transpiration rate decreased 50.67% and the water use efficiency increased 33.70%;In group T3 the seedlings of Acanthopanax Senticosus had lowest net photosynthesis rate and transpiration rate,but the water use efficiency 77.51% higher than that of group CK.In the whole water treatment period,content of proline and MDA increased as the water stress degree was increased.The results indicated that the Acanthopanax Senticosus seedings could fight a drought,but did not fit the dry soil water condition.