Effects of nitrogen application rate and leaf age on the distribution pattern of leaf SPAD readings in the rice canopy.
Effects of nitrogen application rate and leaf age on the distribution pattern of leaf SPAD readings in the rice canopy.
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施氮量和叶龄对水稻冠层叶片SPAD读数分布格局的影响
DOI：
10.1371/journal.pone.0088421
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发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
He J
中科院分区：
文献类型：
--
作者：
Yang H;Li J;Yang J;Wang H;Zou J;He J
土壤-植物分析发展(SPAD)叶绿素仪可以作为一种简单的工具来评估叶片中的氮浓度，并研究氮肥用量和叶龄对氮素分布的综合影响。我们在连续两年(2008-2009年)的水田里用6种不同氮肥水平处理的水稻植株进行了试验。根据单叶中N浓度的时间动态，由SPAD读数确定N的分布格局。在2008年和2009年移栽后62天和2009年移栽后60天，接受150~375 kg ha−1氮素水平的水稻冠层中，叶片SPAD读数从上到下依次增加。然而，随着植物的生长，冠层叶中SPAD读数的这种非典型分布迅速逆转为一般顺序。此外，叶片SPAD读数(N浓度)的时间动态符合分段函数。在我们的模型中，叶片SPAD读数的变化分为三个阶段：生长期、功能期和衰老期。叶片生长期约为6d，累积生长天数不受施氮量的影响。叶片功能期表现为与施氮量相关的相对稳定的SPAD读数，累积生育期随施氮量的增加而延长。用二次方程描述了叶片衰老期SPAD读数与叶龄的关系。SPAD读数的下降速度随着叶龄的增加而增加，但施氮减缓了下降的速度。由于下层树冠的叶片在生理上比上层树冠的叶片老，所以下层树叶的SPAD读数下降的速度更快。
A Soil-Plant Analysis Development (SPAD) chlorophyll meter can be used as a simple tool for evaluating N concentration of the leaf and investigating the combined effects of nitrogen rate and leaf age on N distribution. We conducted experiments in a paddy field over two consecutive years (2008–2009) using rice plants treated with six different N application levels. N distribution pattern was determined by SPAD readings based on the temporal dynamics of N concentrations in individual leaves. At 62 days after transplantation (DAT) in 2008 and DAT 60 in 2009, leaf SPAD readings increased from the upper to lower in the rice canopy that received N levels of 150 to 375 kg ha−1The differences in SPAD readings between the upper and lower leaf were larger under higher N application rates. However, as plants grew, this atypical distribution of SPAD readings in canopy leaf quickly reversed to the general order. In addition, temporal dynamics of the leaf SPAD readings (N concentrations) were fitted to a piecewise function. In our model, changes in leaf SPAD readings were divided into three stages: growth, functioning, and senescence periods. The leaf growth period lasted approximately 6 days, and cumulative growing days were not affected by N application rates. The leaf functioning period was represented with a relatively stable SPAD reading related to N application rate, and cumulative growing days were extended with increasing N application rates. A quadratic equation was utilized to describe the relationship between SPAD readings and leaf age during the leaf senescence period. The rate of decrease in SPAD readings increased with the age of leaves, but the rate was slowed by N application. As leaves in the lower canopy were physiologically older than leaves in the upper canopy, the rate of decrease in SPAD readings was faster in the lower leaves.
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影响因子：
4.2
作者：
Milroy, SP;Bange, MP;Sadras, VO
通讯作者：
Sadras, VO
影响因子：
5.8
作者：
Shiratsuchi, H;Yamagishi, T;Ishii, R
通讯作者：
Ishii, R
影响因子：
7.4
作者：
Bertheloot, Jessica;Martre, Pierre;Andrieu, Bruno
通讯作者：
Andrieu, Bruno
影响因子：
2.7
作者：
FIELD, C
通讯作者：
FIELD, C
影响因子：
2.7
作者：
HIKOSAKA, K;TERASHIMA, I;KATOH, S
通讯作者：
KATOH, S