NITROGEN USE EFFICIENCY IN GROWTH OF POLYGONUM-CUSPIDATUM SIEB ET ZUCC
NITROGEN USE EFFICIENCY IN GROWTH OF POLYGONUM-CUSPIDATUM SIEB ET ZUCC
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DOI：
10.1093/oxfordjournals.aob.a086839
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发表时间：
1984-01-01
期刊：
影响因子：
4.2
通讯作者：
HIROSE, T
中科院分区：
文献类型：
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作者：
HIROSE, T
研究了不同营养条件下砂培虎杖的生长情况。氮素有效性是通过单位根重的吸收速率而不是根量来影响植物对氮素的吸收。反过来，不同数量的N吸收影响植物生长，通过其对叶片扩展速率的影响。净同化率（NAR）随单位叶面积氮含量（C）的增加而增加，但进一步增加叶氮会导致NAR收益递减。通过对NAR和C之间的曲线关系从原点画切线，可以确定使叶片干物质生产最大化的最佳单位叶面积氮含量（Copt）。该最佳含量沿N含量轴沿着划分N限制范围（C < Copt）和C限制范围（C > Copt）。在氮素限制条件下，植株碳库越大，其干物质生产的氮素利用效率越高。这从定性上解释了在氮素供应有限的情况下，冠根比降低的原因。
The growth of P. cuspidatum in sand culture was analyzed under varying nutrient conditions. N availability influenced N uptake of plants through the uptake rate per unit root weight rather than the amount of root. In turn, the different amounts of N taken up affected plant growth through their effects on the rate of leaf expansion. Net assimilation rate (NAR) increased with N content per unit leaf area (C), but further increase in leaf N caused diminishing returns of NAR. Optimal N content per unit leaf area (Copt) to maximize dry-matter production of a leaf could be determined by drawing a tangent from the origin to a curvilinear relation between NAR and C. This optimal content divides a N-limiting range (C < Copt) from a C-limiting one (C > Copt) along the axis of N content. Under N limitation, efficiency of N use in dry matter production could increase if the plant had a larger C sink. This gives a qualitative explanation to reduced shoot-to-root ratio under limited availability of N.