通过土培试验，进行磷素胁迫条件下不同杉木(Cunninghamia lanceolata)无性系磷素特性的比较研究。结果表明：在磷胁迫条件下不同杉木无性系的干物质积累、磷素吸收效率和磷素利用效率均存在显著差异。随着磷胁迫的加剧，不同杉木无性系的干物质积累量和磷素吸收效率下降，而磷素利用效率增强。总体而言，8、9、24、37 号无性系的干物质积累量受胁迫影响最小，23号无性系受胁迫影响最大。其中8号无性系的磷素吸收和利用效率均较高，24、37号无性系的磷素吸收效率较高，而9号无性系的磷素利用效率较高，23号无性系的磷素吸收和利用效率均较低。 在磷胁迫条件下，杉木无性系可通过提高磷素吸收效率和利用效率途径来提高杉木对环境磷素的利用。
Background and Aims Phosphorus（P）deficiency is one of the main factors that influence plant productivity in agricultural and forestry systems. Fertilization and soil improvement are the primary practices used to meet the P demands of crops in traditional agriculture and of trees in forestry management. Chinese fir (Cunninghamia lanceolata), a fast-growing, evergreen coniferous tree with high yield and quality of wood, is the most important tree species of timber plantations in subtropical China. Since Chinese fir plantations range from about 20° to 30° N in latitude and 100° to 120° E in longitude, there are many different genotypes of Chinese fir among the forests in south China. Therefore, it is possible to select the Chinese fir clone with high phosphorus use efficiency.
Methods Based on the pot experiment under the different phosphorus deficiency stress (heavy, medium, slight phosphorus deficiency and normal phosphorus supply), the dry matter accumulation, phosphorus absorption efficiency, and phosphorus use efficiency of eight different Chinese fir clones were analyzed to compare their phosphorus characteristics.
Key Results There were significant differences in the dry matter accumulation, phosphorus absorption efficiency and phosphorus use efficiency among different clones under phosphorus stress. The dry matter accumulation and phosphorus absorption efficiency of different clones decreased whereas phosphorus use efficiency increased with increasing phosphorus stress. The dry matter accumulation of Clone 8, 9, 24 and 37 were influenced by phosphorus stress less than those of the other clones. Phosphorus stress significantly affected the dry matter accumulation of Clone 23. Higher phosphorus absorption and use efficiency in Clone 8, higher phosphorus absorption efficiency in Clone 24 and 37, and higher phosphorus use efficiency Clone 9 were found under phosphorus stress. However, the phosphorus absorption efficiency and phosphorus use efficiency of Clone 23 were lower than those of the other 7 clones.
Conclusion High phosphorus absorption and use efficiency of Chinese fir are the major adaptive strategy under environment with low phosphorus availability.