用改良半叶法测定松树的光合速率

Photosynthetic Rate Measurement of Pinus Trees by Improved Half-leaf Method

论证了用半叶法测定松树光合速率的可行性和可靠性,并总结了该方法测定松树光合速率的优缺点。该方法的操作流程为:环割选定的松枝并在针叶基部涂抹10%的三氯乙酸,中断有机物的运输;然后在该松枝环割处上方选择20束针叶为一个研究对象,每束针叶中的其中1根针叶作为暗保存叶片,另选1根针叶留在松枝上进行光合作用,光合时间不少于4 h;并由此获得两份半叶的干重光合产物总干重及总光合速率。

The feasibility, reliability, merits and demerits of photosynthetic rate measurement of Pinus trees were analyzed by half-leaf method. The operation process was as follows. First, girdling selected Pinus branch and painting 10% trichloroacetie acid （TCA） on the base of needles to interrupt organics transport, then selecting twenty needle bunches on the top of the girdled branch as one study object. One needle of each needle bunch was placed in dark condition, and the other one was kept on the branch to photosynthesize. The photosynthesis time was at least four hours. The twenty needles placed in dark condition were regarded as dark half-leaf, the other twenty photosynthesizing needles as light half- leaf. The two parts of half-leaves were baked to constant dry weight.