缺磷是限制目前农林业产量的一个重要因子，传统的农林业生产主要通过施肥和土壤改良来满足植物对磷的需求，近年来人们开始发掘磷高效利用植物来替代传统方法提高磷的利用效率。杉木(Cunninghamia lanceolata)是我国亚热带地区最重要的造林树种之一，生长快、材质好、产量高，在中国人工林经营中占有重要地位。为揭示磷素胁迫条件下杉木无性系酸性磷酸酶的变化规律和筛选磷高效利用杉木无性系，通过土培试验，设计4种磷素处理水平(正常供磷16 mg•kg－1、轻度磷胁迫8 mg•kg－1、中度磷胁迫4 mg•kg－1、重度磷胁迫0 mg•kg－1)，进行磷素胁迫条件下不同杉木无性系酸性磷酸酶(APA)活性的比较研究。结果表明：缺磷条件下1年生杉木叶片和根际的APA活性明显高于正常供磷处理。随缺磷时间的延长、不同杉木无性系酸性磷酸酶的变化规律不同，其中8号、24号、37号无性系叶片和根际的APA活性明显高于正常供磷处理；5号、9号无性系根际APA活性虽然增幅较大，但其叶片酶活性变化较小；3号、23号、34号无性系整体而言对磷胁迫不敏感，缺磷条件不对其叶片APA及根系APA活性造成显著影响。在磷胁迫条件下，杉木无性系可通过叶片及根际酸性磷酸酶活性的增强来适应环境磷缺乏，但不同杉木无性系对磷缺乏的适应性存在明显差异，因此能否将APA活性作为杉木无性系磷效率的评价指标之一仍需作进一步研究。
Phosphorus (P) deficiency is one of the main factors that influences plant productivity in agricultural and forestry systems. Fertilization and soil improvement are the primary measures used to meet the P demands of crops in traditional agriculture and trees in forestry management. Recently, plants with high phosphorus use efficiency have been discovered and used to replace traditional measures for improving phosphorus use efficiency of corps. Chinese fir (Cunninghamia lanceolata), a fast-growing, evergreen conifer tree with high yield and excellent wood quality, is the most important tree species of timber plantations in subtropical China. In order to understand the P demands of Chinese fir clones, levels of acid phosphatase (APA) activity were studied in the leaves and rhizosphere soil of different potted Chinese fir clones under different levels of phosphorus additions. The potted Chinese fir clones were subjected to four P supply levels: normal P supply (16 mg•kg－1), slight P deficiency (8 mg•kg－1), medium phosphorus deficiency (4 mg•kg－1) and heavy phosphorus deficiency (0 mg•kg－1). The results showed that the activities of APA in the leaves and rhizosphere soil under the P-deficiency treatment were higher than those under normal P treatment, and there were significant differences in the levels of APA activity among the 8 Chinese fir clones. The activities of APA in the leaves and rhizosphere soil of clones 8, 24 and 37 under the P-deficiency treatment were much higher than those under normal P treatment. Compared with the APA levels in leaves, the activities of APA in the rhizosphere soil of clones 5 and 9 under the P-deficiency treatment had higher amplitudes than those under normal P treatment. The clones 3, 23 and 34 were insensitive to P stress, and there were no significant treatment effects on APA levels for these clones. Under the P-deficiency treatment, the activities of APA in the leaves and rhizosphere soil of different Chinese fir clones increased in response to the P stressed environment, and there were significant differences in the abilities of the different Chinese fir clones to adapt to low P levels. Therefore, more research is needed in order to determine whether APA level is an important index for evaluating and selecting Chinese fir clones with high phosphorus use efficiency.