Profiles of leaf nitrogen and light in reproductive canopies of cotton (Gossypium hirsutum)
Profiles of leaf nitrogen and light in reproductive canopies of cotton (Gossypium hirsutum)
复制标题
DOI：
10.1006/anbo.2000.1344
复制
发表时间：
2001-03-01
期刊：
影响因子：
4.2
通讯作者：
Sadras, VO
中科院分区：
文献类型：
--
作者：
Milroy, SP;Bange, MP;Sadras, VO
在营养生长过程中，氮 (N) 的垂直分布通常与冠层内的光分布分布平行。就冠层光合作用而言，这比叶片氮的均匀分布更有优势。我们研究了生殖生长和氮供应对灌溉棉花作物（Gossypium hirsutum L.）冠层氮和光分布的影响。从生殖生长开始后不久直至作物成熟期间定期取样。每两周，将冠层的 1 m(2) 样本切割成厚度相等的四个连续垂直层。测量各层的叶面积和氮浓度（%）。随着生殖发育的进行，垂直氮梯度变得更加明显。据推测，由于与其他物种相比，生殖发育开始后的生长速度较高，并且该阶段的持续时间较长，因此维持氮梯度所产生的整个冠层光合作用效益可能会得到增强。层中叶片氮浓度的下降速率与叶片中的初始浓度或层内的沸腾负荷无关。 (C) 2001 年植物学公司年鉴。
During vegetative growth, the vertical profile of leal' nitrogen (N) often parallels the profile of light distribution within the canopy. This is more advantageous in terms of canopy photosynthesis than a uniform distribution of leaf N. We investigated the influence of both reproductive growth and N supply on the profiles of N and light in canopies of irrigated cotton crops (Gossypium hirsutum L.). Regular samplings were made from soon after the onset of reproductive growth until crop maturity. Every 2 weeks, a 1 m(2) sample of the canopy was cut in four successive vertical layers of equal thickness. Leaf area and N concentration (%) in each layer were measured. The vertical N gradient became more marked with ongoing reproductive development. It is hypothesized that because of the high rate of growth after the onset of reproductive development and the long duration of this phase compared to other species, the whole canopy photosynthetic benefit that would accrue from maintaining the N gradient is likely to be accentuated. The rate of decline in leaf N concentration in a layer was not related to either the initial concentration in the leaves nor the boil load within the layer. (C) 2001 Annals of Botany Company.