A new optical leaf-clip meter for simultaneous non-destructive assessment of leaf chlorophyll and epidermal flavonoids

We have characterized a new commercial chlorophyll (Chl) and flavonoid (Flav) meter called Dualex 4 Scientific (Dx4). We compared this device to two other Chl meters, the SPAD-502 and the CCM-200. In addition, Dx4 was compared to the leaf-clip Dualex 3 that measures only epidermal Flav. Dx4 is factory-calibrated to provide a linear response to increasing leaf Chl content in units of µg cm–2, as opposed to both SPAD-502 and CCM-200 that have a non-linear response to leaf Chl content. Our comparative calibration by Chl extraction confirmed these responses. It seems that the linear response of Dx4 derives from the use of 710 nm as the sampling wavelength for transmittance. The major advantage of Dx4 is its simultaneous assessment of Chl and Flav on the same leaf spot. This allows the generation of the nitrogen balance index (NBI) used for crop surveys and nitrogen nutrition management. The Dx4 leaf clip, that incorporates a GPS receiver, can be useful for non-destructive estimation of leaf Chl and Flav contents for ecophysiological research and ground truthing of remote sensing of vegetation. In this work, we also propose a consensus equation for the transformation of SPAD units into leaf Chl content, for general use.

[1]  Huan Yu,et al.  Evaluation of SPAD and Dualex for in-season corn nitrogen status estimation. , 2010 .

[2]  R. A. Marenco,et al.  Relationship between specific leaf area, leaf thickness, leaf water content and SPAD-502 readings in six Amazonian tree species , 2009, Photosynthetica.

[3]  F. Castelli,et al.  Non-destructive determination of leaf chlorophyll content in four crop species , 1996 .

[4]  L. P. Bidel,et al.  Relationships between optically assessed polyphenols and chlorophyll contents, and leaf mass per area ratio in woody plants: a signature of the carbon-nitrogen balance within leaves? , 2006, Plant, cell & environment.

[5]  Andrew D. Richardson,et al.  An evaluation of noninvasive methods to estimate foliar chlorophyll content , 2002 .

[6]  Paul Jarvis,et al.  Use of a SPAD-502 meter to measure leaf chlorophyll concentration in Arabidopsis thaliana , 2011, Photosynthesis Research.

[7]  Ismael Moya,et al.  The use of chlorophyll fluorescence excitation spectra for the non‐destructive in situ assessment of UV‐absorbing compounds in leaves , 2002 .

[8]  Thomas C. Vogelmann,et al.  Plant Tissue Optics , 1993 .

[9]  A. Allsopp.  The Leaf , 1957, Nature.

[10]  R. Marquard,et al.  Relationship Between Extractable Chlorophyll and an in Situ Method to Estimate Leaf Greenness , 1987, HortScience.

[11]  Nicolas Tremblay,et al.  The Dualex - a new tool to determine nitrogen sufficiency in broccoli. , 2009 .

[12]  Z. Cerovic,et al.  Optically assessed contents of leaf polyphenolics and chlorophyll as indicators of nitrogen deficiency in wheat (Triticum aestivum L.) , 2005 .

[13]  Kenneth G. Cassman,et al.  Adjustment for Specific Leaf Weight Improves Chlorophyll Meter's Estimate of Rice Leaf Nitrogen Concentration , 1993 .

[14]  H. Pleijel,et al.  Evaluating the relationship between leaf chlorophyll concentration and SPAD-502 chlorophyll meter readings , 2007, Photosynthesis Research.

[15]  Caroline Mohammed,et al.  Chlorophyll and nitrogen determination for plantation-grown Eucalyptus nitens and E. globulus using a non-destructive meter , 2006 .

[16]  Ulrich Schreiber,et al.  Measurement of leaf epidermal transmittance of UV radiation by chlorophyll fluorescence , 1997 .

[17]  Yves Goulas,et al.  Dualex: a new instrument for field measurements of epidermal ultraviolet absorbance by chlorophyll fluorescence. , 2004, Applied optics.

[18]  Gregory A Carter,et al.  Optical properties of intact leaves for estimating chlorophyll concentration. , 2002, Journal of environmental quality.

[19]  Ismael Moya,et al.  Ultraviolet-induced fluorescence for plant monitoring: present state and prospects , 1999 .

[20]  J. Markwell,et al.  Calibration of the Minolta SPAD-502 leaf chlorophyll meter , 2004, Photosynthesis Research.

[21]  K. Solhaug,et al.  Effect of Irradiance on Chlorophyll Estimation with the Minolta SPAD-502 Leaf Chlorophyll Meter , 1998 .

[22]  K. Inada,et al.  Studies on a Method for Determining the Deepness of Green and Color Chlorophyll Content of Intact Crop Leaves and Its Practical Applcations : 1. Principle for estimating the deepness of green color and chlorophyll content of whole leaves , 1963 .

[23]  Nicolas Tremblay,et al.  Sensing crop nitrogen status with fluorescence indicators. A review , 2011, Agronomy for Sustainable Development.

[24]  Giovanni Agati,et al.  Nondestructive evaluation of anthocyanins in olive (Olea europaea) fruits by in situ chlorophyll fluorescence spectroscopy. , 2005, Journal of agricultural and food chemistry.

[25]  W. Bilger,et al.  Epidermal transmittance of leaves of Vicia faba for UV radiation as determined by two different methods , 2004, Photosynthesis Research.

[26]  Evaluation of SPAD and Dualex for In-Season Corn Nitrogen Status Estimation: Evaluation of SPAD and Dualex for In-Season Corn Nitrogen Status Estimation , 2010 .

[27]  A. Strever,et al.  The development of a method for the extraction of carotenoids and chlorophylls from grapevine leaves and berries for HPLC profiling , 2010 .

[28]  S. Fujimura,et al.  Nondestructive measurement of chlorophyll pigment content in plant leaves from three-color reflectance and transmittance. , 1991, Applied optics.

[29]  E. Pfündel,et al.  Effects of natural intensities of visible and ultraviolet radiation on epidermal ultraviolet screening and photosynthesis in grape leaves. , 2001, Plant physiology.

[30]  Junichi Imanishi,et al.  Nondestructive determination of leaf chlorophyll content in two flowering cherries using reflectance and absorptance spectra , 2010, Landscape and Ecological Engineering.

[31]  Emile S. Gardiner,et al.  Modeling the relationship between extractable chlorophyll and SPAD-502 readings for endangered plant species research , 2009 .

[32]  D. Arnon.  COPPER ENZYMES IN ISOLATED CHLOROPLASTS. POLYPHENOLOXIDASE IN BETA VULGARIS. , 1949, Plant physiology.

[33]  R. J. Porra,et al.  Determination of accurate extinction coefficients and simultaneous equations for assaying chlorophylls a and b extracted with four different solvents: verification of the concentration of chlorophyll standards by atomic absorption spectroscopy , 1989 .

[34]  J. Řebíček,et al.  SPAD chlorophyll meter reading can be pronouncedly affected by chloroplast movement , 2010, Photosynthesis Research.

[35]  G. Liakopoulos,et al.  The photoprotective role of epidermal anthocyanins and surface pubescence in young leaves of grapevine (Vitis vinifera). , 2006, Annals of botany.

[36]  P. Jarvis,et al.  Erratum to: Use of a SPAD-502 meter to measure leaf chlorophyll concentration in Arabidopsis thaliana , 2011, Photosynthesis Research.

[37]  Nicolas Tremblay,et al.  PERFORMANCE OF DUALEX IN SPRING WHEAT FOR CROP NITROGEN STATUS ASSESSMENT, YIELD PREDICTION AND ESTIMATION OF SOIL NITRATE CONTENT , 2009 .

[38]  Christopher Baraloto,et al.  Assessing foliar chlorophyll contents with the SPAD-502 chlorophyll meter: a calibration test with thirteen tree species of tropical rainforest in French Guiana , 2010, Annals of Forest Science.

[39]  J. Woolley.  Reflectance and transmittance of light by leaves. , 1971, Plant physiology.

[40]  Ronald J. Ryel,et al.  Non‐invasive measurements of leaf epidermal transmittance of UV radiation using chlorophyll fluorescence: field and laboratory studies , 2000 .

[41]  A. Wellburn.  The Spectral Determination of Chlorophylls a and b, as well as Total Carotenoids, Using Various Solvents with Spectrophotometers of Different Resolution* , 1994 .