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1.
Analyses of the correlation between hyperspectral reflectance and pigment content including chlorophyll-a, chlorophyll-b and
carotenoid of leaves in different sites of rice were reported in this paper. The hyperspectral reflectance of late rice during
the whole growing season was measured using a Spectroradiometer with spectral range of 350–1050 nm and resolution of 3 nm.
The chlorophyll-a, chlorophyll-b and carotenoid contents in rice leaves in rice fields to which different levels of nitrogen
were applied were measured. The chlorophyll-a content of upper leaves was well correlated with the spectral variables. However,
the correlation between both chlorophyll-b and caroteniod and the spectral variables was far from that of chlorophyll-a. The
potential of hyperspectral reflectance measurement for estimating chlorophyll-a of upper leaves was evaluated using univariate
correlation and multivariate regression analysis methods with different types of predictors. This study showed that the most
suitable estimated model of chlorophyll-a of upper leaves was obtained by using some hyperspectral variables such asSD
r,SD
b and their integration.
Project (No. 40171065) supported by the National Natural Science Foundation of China. 相似文献
2.
INTRODUCTIONPigmentsarecloselyrelatedtothephysiolog icalfunctionofleaves.Chlorophyllsabsorblightenergyandtransferitintothephotosyntheticpro cess.Carotenoids (yellowpigments)canalsocontributeenergytothephotosyntheticsystem .Becauseoftheimportanceofpigments… 相似文献
3.
不同抗性的向日葵品种接种锈菌后叶片中可溶性蛋白、可溶性总糖及叶绿素含量的变化 总被引：2，自引：0，他引：2
通过对两个不同抗性向日葵品种在苗期接种向日葵锈菌,测定了接种后不同时间叶片的可溶性总糖、可溶性蛋白及叶绿素含量的变化．研究结果表明：抗病品种的可溶性总糖比感病品种高;可溶性蛋白质含量、叶绿素b含量和类胡萝卜素含量的变化与向日葵抗病性有密切关系,而和叶绿素a含量的变化与抗病性没有直接关系． 相似文献
4.
To further develop the methods to remotely sense the biochemical content of plant canopies,we report the results of an experiment to estimate the concentrations of three biochemical variables of corn,i.e.,nitrogen (N),crude fat (EE) and crude fiber (CF) concentrations,by spectral reflectance and the first derivative reflectance at fresh leaf scale.The correlations between spectral reflectance and the first derivative transformation and three biochemical variables were analyzed,and a set of estimation models were established using curve-fitting analyses.Coefficient of determination (R2),root mean square error (RAISE) and relative error of prediction (PEP) of estimation models were calculated for the model quality evaluations,and the possible opti-mum estimation models of three biochemical variables were proposed,with R2 being 0.891,0.698 and 0.480 for the estimation models of N,EE and CF concentrations,respectively.The results also indicate that using the first derivative reflectance was better than using raw spectral reflectance for all three biochemical variables estimation,and that the first derivative reflectances at 759 nm,1954 nm and 2370 nm were most suitable to develop the estimation models of N,EE and CF concentrations,respectively.In addition,the high correlation coefficients of the theoretical and the measured biochemical parameters were obtained,especially for nitrogen (r=0.948). 相似文献
5.
Fu-min Wang Jing-feng Huang Qi-fa Zhou Xiu-zhen Wang 《Journal of Zhejiang University. Science. B》2008,9(12):953-963
The objectives of the study were to select suitable wavebands for rice leaf area index (LAI) estimation using the data acquired over a whole growing season, and to test the efficiency of the selected wavebands by comparing them with feature positions of rice canopy spectra. In this study, the field experiment in 2002 growing season was conducted at the experimental farm of Zhejiang University, Hangzhou, China. Measurements of hyperspectral reflectance (350-2500 nm) and corresponding LAI were made for a paddy rice canopy throughout the growing season. And three methods were employed to identify the optimal wavebands for paddy rice LAI estimation: correlation coefficient-based method, vegetation index-based method, and stepwise regression method. This research selected 15 wavebands in the region of 350-2500 nm, which appeared to be the optimal wavebands for the paddy rice LAI estimation. Of the selected wavebands, the most frequently occurring wavebands were centered around 554, 675, 723, and 1633 nm. They were followed by 444, 524, 576, 594, 804, 849, 974, 1074, 1219, 1510, and 2194 nm. Most of them made physical sense and had their counterparts in spectral known feature positions, which indicates the promising potential of the 15 selected wavebands for the retrieval of paddy rice LAI. 相似文献
6.
ＩＮＴＲＯＤＵＣＴＩＯＮＶｉｓｉｂｌｅａｎｄｎｅａｒｉｎｆｒａｒｅｄｒｅｆｌｅｃｔｉｏｎｓｐｅｃｔｒｏｓ ｃｏｐｙｗａｓｐｒｏｖｅｄｉｎｒｅｃｅｎｔｙｅａｒｓｔｏｏｆｆｅｒｔｈｅｐｏｓ ｓｉｂｉｌｉｔｙｏｆｏｂｔａｉｎｉｎｇａｒａｐｉｄ ,ｎｏｎ ｄｅｓｔｒｕｃｔｉｖｅｅｓｔｉ ｍａｔｉｏｎｏｆｐｌａｎｔｎｉｔｒｏｇｅｎｃｏｎｔｅｎｔｓ(Ｔｈｏｍａｓｅｔａｌ.,1 972 ;Ｈｉｎｚｍａｎｅｔａｌ.,1 986;Ｔａｋｅｂｅｅｔａｌ.,1 990 ;Ｆｉｌｅｌｌａｅｔａｌ.,1 995;Ｂｌａｃｋｍｅｒｅｔａｌ.,1 994 ,1 996;Ｌａｄｈａ… 相似文献
7.
A field experiment was conducted to study the response of individual leaf spectral reflectance to five levels of nitrogen
fertilizer treatments in rice (Oriza sativa L.) plants. Sampling was combined through a rice canopy at upper, medium and low levels for biomass, nitrogen and water content
measurements with spectral signals from the leaves. The vertical gradients of leaf biomass, nitrogen and water contents were
associated with the nitrogen availability during tillering, panicle formation, initial heading and heading. Rice plants treated
with the lowest rate of N could be characterized with the lowest value of gradient in leaf biomass and leaf water content
and the highest value of gradient in leaf N concentration. A spectral gradient of single reflectance (R), ratio (RVI) and
normalized difference (ND) of two individual reflectances was defined as this yielded a better relationship between the spectral
data and leaf nitrogen concentration. The results suggested the spectral gradients may be used as an improved diagnostic tool
for nitrogen status.
Project (49771056) supported by Natural Science Foundation of China(NSFC). 相似文献
8.
Liu ZY Huang JF Shi JJ Tao RX Zhou W Zhang LL 《Journal of Zhejiang University. Science. B》2007,8(10):738-744
Detecting plant health conditions plays a key role in farm pest management and crop protection. In this study, measurement of hyperspectral leaf reflectance in rice crop (Oryzasativa L.) was conducted on groups of healthy and infected leaves by the fungus Bipolaris oryzae (Helminthosporium oryzae Breda. de Hann) through the wavelength range from 350 to 2 500 nm. The percentage of leaf surface lesions was estimated and defined as the disease severity. Statistical methods like multiple stepwise regression, principal component analysis and partial least-square regression were utilized to calculate and estimate the disease severity of rice brown spot at the leaf level. Our results revealed that multiple stepwise linear regressions could efficiently estimate disease severity with three wavebands in seven steps. The root mean square errors (RMSEs) for training (n=210) and testing (n=53) dataset were 6.5% and 5.8%, respectively. Principal component analysis showed that the first principal component could explain approximately 80% of the variance of the original hyperspectral reflectance. The regression model with the first two principal components predicted a disease severity with RMSEs of 16.3% and 13.9% for the training and testing dataset, respec-tively. Partial least-square regression with seven extracted factors could most effectively predict disease severity compared with other statistical methods with RMSEs of 4.1% and 2.0% for the training and testing dataset, respectively. Our research demon-strates that it is feasible to estimate the disease severity of rice brown spot using hyperspectral reflectance data at the leaf level. 相似文献
9.
Zhan-yu Liu Jing-jing Shi Li-wen Zhang Jing-feng Huang 《Journal of Zhejiang University. Science. B》2010,11(1):71-78
Detection of crop health conditions plays an important role in making control strategies of crop disease and insect damage and gaining high-quality production at late growth stages. In this study, hyperspectral reflectance of rice panicles was measured at the visible and near-infrared regions. The panicles were divided into three groups according to health conditions: healthy panicles, empty panicles caused by Nilaparvata lugens Stul, and panicles infected with Ustilaginoidea virens. Low order derivative sp... 相似文献
10.
INTRODUCTION Recently increasing demands from consumerhave been observed for premium quality fruit witbetter taste at a higher price. Three major parameters determine the internal quality and the tastof apples. These are hardness, sugar content antitratable acidity, which are still determined destructively. Near-infrared spectroscopy (NIRS) habeen used to nondestructively measure internquality in a wide range of fruits and vegetablesuch as onions (Birth et al., 1985), cantaloupe (… 相似文献
11.
To evaluate the potential of FT-NIR spectroscopy and the influence of the distance between the light source/detection probe and the fruit for measuring the sugar content (SC) of Fuji apples, diffuse reflectance spectra were measured in the spectral range from 12500 to 4000 cm(1 at 0 mm, 2 mm, 4 mm and 6 mm distances. Four calibration models at four distances were established between diffused reflectance spectra and sugar content by partial least squares (PLS) analysis. The correlation coefficients (R) of calibrations ranged from 0.982 to 0.997 with SEC values from 0.138 to 0.453 and the SECV values from 0.74 to 1.58. The best model of original spectra at 0 mm distance yielded high correlation determination of 0.918, a SEC of 0.092, and a SEP of 0.773. The results showed that different light/detection probe-fruit distances influence the apple reflective spectra and SC predictions. 相似文献
12.
高光谱植被指数与水稻叶片叶绿素相关分析 总被引：1，自引：0，他引：1
利用野外地物光谱仪Avafield-1测定水稻灌浆晚期三个品种的叶片光谱曲线,将所测的光谱反射率值计算得到11个植被指数,分析植被指数与同期所测叶片叶绿素值关系.结果表明品种三与其他两个品种在灌浆晚期光谱曲线差异较为明显,植被指数对于灌浆晚期叶片叶绿素相关性较低,最大相关值0.83是修正归一化差异指数与叶绿素计算所得. 相似文献
13.
Qi-fa Zhou Zhan-yu Liu Jing-feng Huang 《Journal of Zhejiang University. Science. B》2010,11(6):465-470
The main objective of this work was to compare the applicability of the single leaf (the uppermost leaf L1 and the third uppermost
leaf L3) modified simple ratio (mSR705 index) and the leaf positional difference in the vegetation index between L1 and L3 (mSR705L1-mSR705L3) in detecting nitrogen (N)-overfertilized rice plants. A field experiment consisting of three rice genotypes and five N fertilization
levels (0, 75, 180, 285, and 390 kg N/ha) was conducted at Xiaoshan, Hangzhou, Zhejiang Province, China in 2008. The hyperspectral
reflectance (350–2500 nm) and the chlorophyll concentration (ChlC) of L1 and L3 were measured at different stages. The mSR705L1 and mSR705L3 indices appeared not to be highly sensitive to the N rates, especially when the N rate was high (above 180 kg N/ha). The
mean mSR705L1-mSR705L3 across the genotypes increased significantly (P<0.05) or considerably from 180 to 285 kg N/ha treatment and from 285 to 390 kg N/ha treatment at all the stages. Also, use
of the difference (mSR705L1-mSR705L3) greatly reduced the influence of the stages and genotypes in assessing the N status with reflectance data. The results of
this study show that the N-overfertilized rice plants can be effectively detected with the leaf positional difference in the
mSR705 index. 相似文献
14.
YANG Xiao-hua HUANG Jing-feng WANG Fu-min WANG Xiu-zhen YI Qiu-xiang WANG Yuan 《浙江大学学报(A卷英文版)》2006,7(12)
INTRODUCTION Great advance has been achieved in vegetation characterization with remote sensing techniques. Most spectral vegetation indices (VIs) are usually calculated as the combinations of red and near-in- frared (NIR) reflectance because the information contained in a single spectral band is insufficient for characterizing vegetation status as vegetation exhibits unique reflectance properties in these bands. These VIs can be generally grouped into ratio indices and orthogonal indic… 相似文献
15.
YANG Xiao-hua HUANG Jing-feng WANG Fu-min WANG Xiu-zhen YI Qiu-xiang WANG Yuan 《浙江大学学报(A卷英文版)》2006,7(12):2002-2006
There is increasing interest in using hyperspectral data for quantitative characterization of vegetation in spatial and temporal scopes. Many spectral indices are being developed to improve vegetation sensitivity by minimizing the background influence. The chlorophyll absorption continuum index （CACI） is such a measure to calculate the spectral continuum on which the analyses are based on the area of the troughs spanned by the spectral continuum, However, different values of CACI were obtained in this method because different positions of continuums were determined by different users. Furthermore, the sensitivity of CACI to agronomic parameters such as green leaf chlorophyll density （GLCD） has been reduced because the fixed positions of continuums are determined when the red edge shifted with the change in GLCD. A modified chlorophyll absorption continuum index （MCACI） is presented in this article. The red edge inflection point （REIP） replaces the maximum reflectance point （MRP） in near-infrared （NIR） shoulder on the CACI continuum. This MCACI has been proved to increase the sensitivity and predictive power of GLCD. 相似文献
16.
尤鑫 《唐山师范学院学报》2012,(2):41-44
以新疆伊犁地区野生核桃(J. fdlax Dode)叶和外果皮为试材,研究了其中提取液的吸收光谱和低温冷冻对色素提取的影响.结果表明核桃叶中的叶绿素在冷藏后明显下降,而核桃外果皮中的叶绿素变化不明显.新鲜野生核桃色素提取液呈淡绿色,冷藏后两者的提取液颜色呈褐色,随时间增加颜色变深.野生核桃的核桃醌易溶于丙酮,影响植物提取液的吸光值.叶中的核桃醌的吸光值随时间的增加而增加;外果皮中的核桃醌的吸光值随时间的增加先减少后增加;颜色稳定,均可用于褐色色素提取. 相似文献
17.
Hui-rong Xu Peng Yu Xia-ping Fu Yi-bin Ying 《Journal of Zhejiang University. Science. B》2009,10(2):126-132
The use of visible-near infrared (NIR) spectroscopy was explored as a tool to discriminate two new tomato plant varieties in China (Zheza205 and Zheza207).In this study,82 top-canopy leaves of Zheza205 and 86 top-canopy leaves of Zheza207 were measured in visible-NIR reflectance mode.Discriminant models were developed using principal component analysis (PCA),discriminant analysis (DA),and discriminant partial least squares (DPLS) regression methods.After outliers detection,the samples were randomly split into two sets,one used as a calibration set (n=82) and the remaining samples as a validation set (n=82).When predicting the variety of the samples in validation set,the classification correctness of the DPLS model after optimizing spectral pretreatment was up to 93%.The DPLS model with raw spectra after multiplicative scatter correction and Savitzky-Golay filter smoothing pretreatments had the best satisfactory calibration and prediction abilities (correlation coefficient of calibration (Rc)=0.920,root mean square errors of calibration=0.196,and root mean square errors of prediction=0.216).The results show that visible-NIR spectroscopy might be a suitable alternative tool to discriminate tomato plant varieties on-site. 相似文献
18.
尤鑫 《楚雄师范学院学报》2012,27(3):59-63
以新疆伊犁地区野生核桃（Juglans fallax）叶和外果皮为试材,研究了其中提取液的吸收光谱和低温冷冻对色素提取的影响。结果表明核桃叶中的叶绿素在冷藏后明显下降,而核桃外果皮中的叶绿素变化不明显。提取液的吸收光谱基本相似,用Lichtenthaler计算公式进行叶绿素含量测定。叶中叶绿素a在冷藏后吸光值明显减小,叶绿素b吸光值减小不明显,但类胡萝卜素却增加了,而野生核桃外果皮中的叶绿素a,b冷藏前后变化不明显,只有类胡萝卜素有明显增加。新鲜野生核桃色素提取液呈淡绿色,冷藏后两者的提取液颜色呈褐色,随时间增加颜色变深。冷藏处理后野生核桃叶色素含量在220nm～420nm波段有吸收峰,提取液放置40小时内吸光值相似,标准偏差0.043,稳定性良好;野生核桃外果皮色素含量在220nm～410nm及420nm～580nm波段有吸收峰,提取液4小时后吸光值相似,标准偏差0.028,稳定性良好,在420nm～580nm之间,0小时的提取液吸光值急剧减少,小于4小时之后提取液的吸光值。野生核桃的核桃醌易溶于丙酮,影响植物提取液的吸光值。叶中的核桃醌的吸光值随时间的增加而增加;外果皮中的核桃醌的吸光值随时间的增加先减少后增加;颜色稳定,均可用于褐色色素提取。 相似文献
19.