水分胁迫对短梗大参生理生化特征的影响

为了探索短梗大参对水分胁迫的适应性,提供其引种驯化和园林栽培依据,以2年生短梗大参苗木为试验材料,采用盆栽试验和称重控水法进行土壤水分胁迫(设置土壤相对含水量分别为田间最大持水量的80%、70%、60%和50%,以田间最大持水量100%为对照),研究不同水分胁迫对短梗大参生理生化特征的影响。结果表明:短梗大参叶片相对含水量随着土壤水分胁迫程度加强而降低,最大降幅达34.50%;质膜在水分胁迫下易遭受破坏,在严重水分胁迫下相对质膜透性高达79.85%,丙二醛(MDA)含量增幅达121.07%;渗透调节物质脯氨酸和可溶性糖的含量在水分胁迫下增加,至土壤相对含水量70%时达到最高,分别比对照升高34.73%和40.39%,而可溶性蛋白质含量下降;总叶绿素、叶绿素a和叶绿素b含量在水分胁迫下降低,而叶绿素a与叶绿素b的比值升高。

Effects of water stress on physiological and biochemical characteristics in Macropanax rosthornii

In order to study adaptation of Macropanax rosthornii to water stresses and to provide bases for introduction and plantation as an ornamental plant, using 2-year-old seedlings of M. rosthornii as experiment materials, the effects of water stress on physiological and biochemical characteristics by pot experiment under different water stresses (the relative soil water contents were set up by 80%, 70%, 60%, and 50% of maximum field capacity respectively, and 100% was the control). The results showed that the relative water content in M. rosthornii leaves was declined as the relative soil water content was decreased, with a maximum decrement up to 34.50%. The plasma membrane was easy to be damaged under water stress, and the relative permeability of plasma membrane was as high as 79.85% and malondialdehyde (MDA) content was increased by 121.07% compared with the control under serious water stress. The contents of osmotic adjustment substances such as proline and soluble sugar were increased under water stress and reached the maximum at the water stress of 70% relative soil water content, increased by 34.73% and 40.39% respectively compared with the control, but the soluble protein content was decreased during the water stress. The contents of total chlorophyll, chlorophyll a and chlorophyll b were decreased with the strengthening of water stress but the ratio of chlorophyll a to chlorophyll b was increased.