断根对菊芋C、N、P化学计量特征的影响

The Influence of Root Cutting on Ecological Stoichiometry of Carbon,Nitrogen,Phosphorus in Helianthus Tuberosus

对营养期菊芋水平根系进行0 m,0.2 m,0.4 m,0.6 m和0.8 m的断根处理,测定根、茎、叶、花、块茎等器官C、N、P含量,计算C:N、C:P和N:P,探讨不同断根条件下菊芋的化学计量特征.结果表明:根、茎、叶、花、块茎等各器官之间碳含量高低顺序没有因断根而改变,氮和磷含量高低顺序因断根半径不同而表现出不同的大小关系;同一器官不同断根条件下,断根半径对碳含量的影响比较相似,而氮和磷含量的影响因器官不同而表现出不同的差异;C:N、C:P和N:P 3组比值因断根处理而表现出不同的变化范围,其值分别为C:N 16.96~177.24,C:P 150.17~877.79,N:P 4.71~17.03;从N:P比值可以看出菊芋生长主要受氮素限制.

The ecological stoichiometry for the Jerusalem artichoke Helianthus tuberosus was studied by monitoring the Carbon（C）,Nitrogen（N）and Potassium（P）content of roots,stems,leaves,flowers,and tubers under different rididius 0,0.2,0.4,0.6 and 0.8 m. Calculation of C：N,C：P and N：P,under different root cutting condition,stoichiometric characteristics of Jerusalem artichoke was discussed. The result showed that the order of carbon content among roots,stems,leaves,flowers and tubers and other organs did not change due to root pruning. The order of nitrogen and phosphorus showed different size relationship because of different cutting root radius. The effect of root cutting radius on carbon content was similar in different cutting roots of the same organ,but the effects of nitrogen and phosphorus content varied with different organs. C：N,C：P and N：P 3 groups showed different variation range with ratio of root cutting treatment,and the values are C：N 16.96-177.24,C：P 150.17-877.79,N：P 4.71-17.03. The N：P ratio showed that the growth of Jerusalem artichoke was mainly affected by nitrogen limitation.