水分胁迫下2种云杉属植物的水分生理特征

为研究沙地云杉(Picea mongolica)和青海云杉(Picea crassifolia)在干旱荒漠区适应性特征,筛选出适宜于干旱荒漠区理想的造林树种,以2种云杉属植物为试验材料,测定正常供水条件、中度土壤水分胁迫、重度土壤水分胁迫条件下2个树种的水分参数。在土壤水分胁迫条件下,2种云杉属植物自由水含量、组织含水量、叶片水势、相对含水量降低,而水分饱和亏、束缚水/自由水、束缚水增大,叶片持水力降低。随着季节的变化,2种云杉属植物各项水分参数受外界环境的影响呈规律性变化,组织含水率在7—9月变化差异不显著,束缚水/自由水、束缚水含量在7—9月呈增加后又下降的趋势;相对含水量呈递增趋势;水分饱和亏呈下降趋势;自由水含量呈下降后又增加的趋势。在水分胁迫初期,2种云杉各处理苗木持水力差异不显著,随着胁迫时间的延长,持水力差异增大,而且青海云杉持水力低于沙地云杉的。从2种云杉属植物各项水分参数分析,表明沙地云杉具有较强的抗逆水分生理特征。

Water Physiological Characteristics of Two Picea Species Under Water Stress

This study aims to research the adaptation characteristics of Picea crassifolia and Picea mongolica in arid desert region, and choose proper forest plants for the arid desert region. The authors took twoPicea species as the materials, measured their water physiological characteristic under normal soil water condition, moderate soil water stress, and severe soil water stress. The results showed that under different water stresses, the free water content, leaf water potential, tissue water content, relative water content of the two species decreased, water saturation deficit, ratio of bound water content to free water content and bound water content increased, and leaf water-holding ability reduced. With the change of season, water parameters of the two species changed regularly affected by the external environment. The variation of the tissue water content was not significant from July to September, the bound water content, ratio of bound water content to free water content showed an increasing and then decreasing trend from July to September; the relative water content showed an increasing trend; the free water content decreased and then showed an increasing trend. In the early days of water stress, the difference of water water-holding ability of the two species was not significant. With the prolonging of water stress time, the difference of water-holding ability increased and the water-holding ability of Picea crassifolia was less than that of Picea mongolica. Picea mongolica had stronger water physiological characteristics by analyzing the water parameters.