Changes in leaf photosynthetic parameters with leaf position and nitrogen content within a rose plant canopy (Rosa hybrida)
Changes in leaf photosynthetic parameters with leaf position and nitrogen content within a rose plant canopy (Rosa hybrida)
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DOI：
10.1046/j.1365-3040.2000.00559.x
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发表时间：
2000-04-01
影响因子：
7.3
通讯作者：
Baille, A
中科院分区：
文献类型：
--
作者：
Gonzalez-Real, MM;Baille, A
本文研究了玫瑰（Rosa Hyda cv. Sonia）植物冠层叶片光合能力随深度的变化。秋季在温室条件下对位于植物冠层不同层的成熟叶片（包括花茎和主芽）进行叶片净CO2同化量（A(l)）和总氮含量（N-l）的测量。这些叶子经受（i）在饱和光合光子通量密度（I约1000μmol m（-2）s（-1））下的对比水平的CO2分压（p（a））和（ii）饱和CO2分压（p（a）约100Pa）和变化的I，而温度条件是温室中的普遍条件（20-38摄氏度）。对每层叶子的 A(l) 与细胞间 CO2 分压 (p(i)) 相关的叶子光合作用生化模型进行参数化，提供相应的光合 Rubisco 容量 (V-lm) 和最大电子传输速率 (J(m)) 值。结果表明，生长在冠层顶部的玫瑰叶片具有较高的 J(m) 和 V-lm 值，这是由于较高的氮分配到最上面的叶片所致。从花茎最上面的叶子到植物底部生长的叶子，叶片总氮N-l的平均值下降了约35%。非光合氮 N-b 的导出值从 76 mmol(N) m(leaf)(-2)（第 1 层）到 60 mmol(N) m(leaf)(-2)（第 4 层）不等，代表 N-l 的很大一部分（第 1 层和第 4 层分别为 50% 和 60%）。叶片光合氮 (N-p = N-l - N-b) 和 I 分布的比较支持了玫瑰叶片适应时间积分吸收 I 的假设。在秋季、春季和夏季获得的 I 和 N-p 之间的关系表明，通过在秋季和春季向叶片分配比夏季更多的光合氮，玫瑰叶片似乎也在季节性地适应其光合能力。
This paper deals with changes in leaf photosynthetic capacity with depth in a rose (Rosa hybrida cv. Sonia) plant canopy. Measurements of leaf net CO2 assimilation (A(l)) and total nitrogen content (N-l) were performed in autumn under greenhouse conditions on mature leaves located at different layers within the plant canopy, including the flower stems and the main shoots. These leaves were subjected (i) to contrasting levels of CO2 partial pressure (p(a)) at saturating photosynthetic photon flux density (I about 1000 mu mol m(-2) s(-1)) and (ii) to saturating CO2 partial pressure (p(a) about 100 Pa) and varying I, while conditions of temperature were those prevailing in the greenhouse (20-38 degrees C). A biochemical model of leaf photosynthesis relating A(l) to intercellular CO2 partial pressure (p(i)) was parameterized for each layer of leaves, supplying corresponding values of the photosynthetic Rubisco capacity (V-lm) and the maximum rate of electron transport (J(m)). The results indicated that rose leaves growing at the top of the canopy had higher values of J(m) and V-lm, which resulted from a higher allocation of nitrogen to the uppermost leaves. Mean values of total leaf nitrogen, N-l, decreased about 35% from the uppermost leaves of flower stem to leaves growing at the bottom of the plant. The derived values of non-photosynthetic nitrogen, N-b, varied from 76 mmol(N) m(leaf)(-2) (layer 1) to 60 mmol(N) m(leaf)(-2) (layer 4), representing a large fraction of N-l (50 and 60% in layer 1 and 4, respectively). Comparison of leaf photosynthetic nitrogen (N-p = N-l - N-b) and I profiles supports the hypothesis that rose leaves acclimate to the time-integrated absorbed I. The relationships between I and N-p, obtained during autumn, spring and summer, indicate that rose leaves seem also to acclimate their photosynthetic capacity seasonally, by allocating more photosynthetic nitrogen to leaves in autumn and spring than in summer.