Dualex
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The Dualex is an optical sensor used in plant science and agriculture for the assessment of flavonol, anthocyanin, and chlorophyll contents in leaves. This device allows researchers to perform real-time and non-destructive measurements of these important plant metabolites, which are crucial indicators of plant health and stress responses. Developed by Force-A (now out of business), the sensor is a result of technology transfer from the CNRS (National Center for Scientific Research) and University of Paris-Sud Orsay.[http://www2.cnrs.fr/en/1465.htm?theme1=10 Four innovative start-ups stemming from CNRS at the European Research and Innovation Exhibition 2009][http://www.ese.u-psud.fr/rubrique88.html?lang=en ESE Presentation - Lab. Ecologie, Systématique, Evolution - Technology Transfer] It allows to make instant measurements without damaging the leaves.{{Cite web |last=Cerovic |first=Zoran G. |title=New proximal sensors of vegetation: towards a non destructive quantitative estimation of plant constituents |url=http://www.ese.u-psud.fr/IMG/pdf/CerovicEbernburg2012.pdf |url-status=dead |archive-url=https://web.archive.org/web/20140822115631/http://www.ese.u-psud.fr/IMG/pdf/CerovicEbernburg2012.pdf |archive-date=2014-08-22 |date=October 2012 |place=Ebernburg |access-date=2024-07-12 }} The main applications are plant sciences and agricultural research.
Calculated parameters
The assessment of polyphenolic compounds in leaves is based on the absorbance of the leaf epidermis through the screening effect it procures to chlorophyll fluorescence. Bilger, W., Veit, M., Schreiber, L., Schreiber, U., 1997. Measurement of leaf epidermal transmittance of UV radiation by chlorophyll fluorescence. Physiologia Plantarum 101, 754-763.Goulas, Y., Cerovic, Z.G., Cartelat, A., Moya, I., 2004. Dualex: A new instrument for field measurements of epidermal UV-absorbance by chlorophyll fluorescence. Appl. Opt. 43, 4488-4496.
The parameters calculated by Dualex are:
- Anth, for the anthocyanin index
- Chl, for the chlorophyll content
- Flav, for the flavonols index
- NBI, for the nitrogen balance index
Applications
Based on the four measured indices, this optical sensor is applied in the fields of research as follows:
- Plant physiologySandrine Barthod, Zoran Cerovic and Daniel Epron. 2007 [https://web.archive.org/web/20110705010259/http://jxb.oxfordjournals.org/content/58/7/1753.full Can dual chlorophyll fluorescence excitation be used to assess the variation in the content of UV-absorbing phenolic compounds in leaves of temperate tree species along a light gradient?] Journal of Experimental Botany. Volume 58. Issue 7. Pp. 1753-1760Sajjad Hussain, Frank Curk, Claudie Dhuique-Mayer, Laurent Urban, Patrick Ollitrault, François Luro, Raphaël Morillon. 2012 [http://www.sciencedirect.com/science/article/pii/S0304423811005905 Autotetraploid trifoliate orange (Poncirus trifoliata) rootstocks do not impact clementine quality but reduce fruit yields and highly modify rootstock/scion physiology] Scientia Horticulturae. Volume 134. Pages 100–107
- Genetic studiesLuis O. M., Riita T., Mikael B., Markku K.,
Anders L. and Pedro J. A. 2010 [https://archive.today/20140818000514/http://treephys.oxfordjournals.org/content/30/7/923.full.pdf+html Effects of solar UV-A and UV-B radiation on gene expression and phenolic accumulation in Betula pendula leaves] Tree Physiology 30, 923–934
It is equally applied in studies related to chlorophyllPadillaa, F.M., Peña-Fleitasa, M.T., Gallardo, M., Thompson, R.B. 2014 [http://www.sciencedirect.com/science/article/pii/S1161030114000471 Evaluation of optical sensor measurements of canopy reflectance and of leaf flavonols and chlorophyll contents to assess crop nitrogen status of muskmelon] Europ. J. Agronomy 58 (2014) 39–52. (nutritional chlorosis, potential photosynthesis), flavonols (UV protection,Pfündel, E.E., Ben Ghozlen, N., Meyer, S., Cerovic, Z.G. 2007 [http://max2.ese.u-psud.fr/publications/PfundelEE2007PhotRes.pdf Investigating UV screening in leaves by two different types of portable UV fluorimeters reveals in vivo screening by anthocyanins and carotenoids] Photosynth. Res., 93:205-221. leaf light environment) and anthocyanins (temperature stress, light selection).