Mechanism of Pinus yunnanensis seedlings root response to phosphorus deficiency under controlled conditions
在控制条件下云南松幼苗根系对低磷胁迫的响应

Phosphorus is an important element that controls the process of plant life, especially during its growth phase. Low-phosphorus in the soil usually leads to adaptive changes to plants. Yunnan Plateau, being origin and its distribution range, Pinus yunnanensis Franch. reflects great capability of adapting to low-phosphorus red soil. Therefore, to study such mechanism of adaptation towards low-phosphorus becomes an important reason to understand basic resource utilization. Present study was to analyze root response of seedlings (Pinus yunnanensis Franch.) to various phosphorus levels looking at the root morphological characters, like biomass and root/shoot ratio. The test results showed that both the length of taproots and the root/shoot ratio increased as phosphorus supply decreased to 0.5mmol/L. However, the number of lateral roots and the biomass did not show any particular change. Further analysis indicated that, under phosphorus deficiency, growth continues maintaining root biomass by assuring dry matter allocation to the roots. Conclusively, such an adaptation by the seedlings does not depend on its number of lateral roots, rather on the increment of taproot's length.