Chlorophyll fluorescence monitoring to diagnose boron and magnesium deficiency on sugar beet
2001
Hermans, C. (Universite libre de Bruxelles (Belgium). Lab. de Physiologie et de Genetique Moleculaire des Plantes) | Strasser, R.J. | Delhaye, J.P.
The early diagnosis of mineral deficiencies is an important issue in agriculture, because it helps to prevent any irreversible loss of crop yield and decrease of crop quality. The detection of the nutrition stress is assessed by a vitality diagnosis that senses the photochemical function. In this way, we suggest a methodology useful to adjust the standard analytical diagnosis of leaf or soil nutrient content. The sensor function of fluorescence arises from the fact that this emission is complementary to alternative pathways of chlorophyll de-excitation, which are mainly heat dissipation and photochemistry. A dark-adapted photosynthetic sample shows a typical fluorescence transient, upon illumination by saturating light. This transient recorded with the fluorometer Plant Efficiency Analyser (Hansatech Instruments) with a time resolution of 10 s, clearly reveals intermediate steps J and I between the origin O and the maximum P. Moreover, it changes shape according to the lack of B or Mg in the mineral nutrition. Taking the advantage of the changes in the shape of the fluorescence signal, a test has been developed (JIP-test) which can be used as a tool for rapid screening of many samples providing adequate information about the structure, conformation and function of the photosynthetic apparatus. Different graphic presentations will be used to analyse the data measured during the installation of the B and Mg deficiency in controlled conditions.
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