雪松、海桐等几种常绿园林树种的电解质外渗率与抗冻性

The Relationship between Conductivity and Freezing Tolerance of Several Ever-green Trees

四月中旬,选取雪松等五种常绿园林树种的离体叶片,经两种不同的温度处理后测其电解质外渗率(%)值。实验结果表明,不同的植物材料,其电解质外渗率(%)值不同,经低温处理后,其电解质外渗率(%)变化的幅度一般针叶树较阔叶树小。低温胁迫使细胞的透性变大,电解质外渗率(%)增大。在春末,电解质外渗率(%)的增减,能从总体上反映出所测试材料的抗冻性,即针叶树较阔叶树抗冻。

The experimental materials used were Cedrus deodara, Crytomeria fortunei, Podocarpus macrophyllus, Pittosp orum tobira and Ligustrum quihoui. The excised leaves were treated with two different temperatures (16±2℃ and -18±2℃). The materials were treated for 3 hrs under different temperatures and immersed in de-ionized water for 3 hrs. The conductivity were determined after this. Results obtained were as follows. Different varieties have different leakage rates. The freezing (-18±2℃) tolerance of needle-leaved trees was higher than that of broad-leaved trees.