中文摘要：

为揭示苹果适应低磷胁迫的机制，以平邑甜茶[Malus hupehensis（Pamp）Rehd．]为材料，采用水培方式研究了缺磷和复磷条件下根系磷吸收和根构型参数的变化。结果显示，平邑甜茶幼苗在缺磷营养液中培养120h期间，根系磷最大吸收速率始终高于对照，并趋向一个较稳定的差值；缺磷处理最初12h内根系磷吸收米氏常数Km值提高，但72—120h明显下降。缺磷处理的平邑甜茶幼苗转到完全营养液中培养12～120h，根系对磷的转运效率影响不大，而与磷的亲和力下降，并逐渐恢复到正常状态。平邑甜茶幼苗在缺磷条件下培养至11d时，一级侧根总长度低于对照，但在17～26d时，一级侧根总长度明显提高。结果表明，平邑甜茶在短期内主要通过磷吸收动力学的变化来适应缺磷胁迫，较长时期则通过根构型的变化来适应。

英文摘要：

To probe into the adaptive mechanism of apple to was made, using Malus hupehensis （Pamp） Rehd. as materials about the dynamic changes Rehd. under the condition phosphorus deficiency, a systematic study and by means of water-culture approach, of uptake of phosphorus by roots and root architecture parameters of M. hupehensis of P-deficiency and re-supplied P. Results revealed that the greatest rate of absorption （ Imax ） of M. hupehensis Rehd. young seedling in P-deficiency nutrient solution was constantly higher than that of M. hupehensis Rehd. young seedling in full Hoagland solution, and tended to be relatively stable in 120 h; Michaelis constant （Km） went up during 0 -12 h, but obviously decreased between 72 h to 120 h. In contrast, the effect of root system on the phosphorus transport efficiency was not remarkable, but the phosphorus affinity decreased and gradually returned to normal from 12 h to 120 h when the plants cultivated in P-deficiency solution were transplanted into and stayed in the full Hoagland solution. In addition, the lengths of primary lateral roots in P-deficiency solution were shorter than that of primary lateral roots in full Hoagland solution on the 1 lth day, and obviously increased from 17th day to 26th day. The results demonstrated that the adaptation of M. hupehensis Rehd. to the condition of phosphorus-deficiency was realized by the changes of parameters of P uptake kinetics during a short time and by the changes of root architecture during a long time.